Date calculator tool

Fuck LocalDateTime, now ZonedDateTime is my new homie squashed commit
2025-06-19 08:45:27 +02:00 · 2023-08-01 22:55:20 +03:00 · 2023-08-01 22:55:20 +03:00 · 79269dcea5
commit 79269dcea5
parent fbcda09c32
19 changed files with 898 additions and 294 deletions
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@ -11,6 +11,7 @@
        android:supportsRtl="true"
        android:theme="@style/Theme.Unitto">
        <activity
+            android:windowSoftInputMode="adjustResize"
            android:name=".MainActivity"
            android:allowTaskReparenting="true"
            android:exported="true">
--- a/core/base/src/main/res/values/strings.xml
+++ b/core/base/src/main/res/values/strings.xml
@ -1370,4 +1370,8 @@ Used in this dialog window. Should be short -->
    <string name="add_time_zone_title">Add time zone</string>
    <string name="middle_zero_option">Zero in the middle</string>
    <string name="middle_zero_option_support">Swap zero and decimal buttons</string>
+    <string name="difference">Difference</string>
+    <string name="add">Add</string>
+    <string name="subtract">Subtract</string>
+    <string name="date_calculator">Date calculator</string>
 </resources>
--- a/core/ui/src/main/java/com/sadellie/unitto/core/ui/common/DateTimePickerDialog.kt
+++ b/core/ui/src/main/java/com/sadellie/unitto/core/ui/common/DateTimePickerDialog.kt
@ -55,7 +55,7 @@ import com.sadellie.unitto.core.base.R
 import java.time.Instant
 import java.time.LocalDateTime
 import java.time.ZoneId
-import java.time.ZoneOffset
+import java.time.ZonedDateTime
 import kotlin.math.max

@Composable
@ -127,13 +127,13 @@ fun TimePickerDialog(
@Composable
 fun DatePickerDialog(
    modifier: Modifier = Modifier,
-    localDateTime: LocalDateTime,
+    localDateTime: ZonedDateTime,
    confirmLabel: String = stringResource(R.string.ok_label),
    dismissLabel: String = stringResource(R.string.cancel_label),
    onDismiss: () -> Unit = {},
-    onConfirm: (LocalDateTime) -> Unit,
+    onConfirm: (ZonedDateTime) -> Unit,
 ) {
-    val pickerState = rememberDatePickerState(localDateTime.toEpochSecond(ZoneOffset.UTC) * 1000)
+    val pickerState = rememberDatePickerState(localDateTime.toEpochSecond() * 1000)

    AlertDialog(
        onDismissRequest = onDismiss,
--- a/feature/datedifference/build.gradle.kts
+++ b/feature/datedifference/build.gradle.kts
@ -29,4 +29,6 @@ android {

 dependencies {
    testImplementation(libs.junit)
+
+    implementation(project(mapOf("path" to ":data:userprefs")))
 }
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/DateDifferenceScreen.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/DateDifferenceScreen.kt
@ -1,234 +0,0 @@
-/*
- * Unitto is a unit converter for Android
- * Copyright (c) 2023 Elshan Agaev
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package com.sadellie.unitto.feature.datedifference
-
-import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.animation.expandVertically
-import androidx.compose.animation.shrinkVertically
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.ExperimentalLayoutApi
-import androidx.compose.foundation.layout.FlowRow
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.compose.ui.unit.dp
-import androidx.hilt.navigation.compose.hiltViewModel
-import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import com.sadellie.unitto.core.base.R
-import com.sadellie.unitto.core.ui.common.DatePickerDialog
-import com.sadellie.unitto.core.ui.common.MenuButton
-import com.sadellie.unitto.core.ui.common.SettingsButton
-import com.sadellie.unitto.core.ui.common.TimePickerDialog
-import com.sadellie.unitto.core.ui.common.UnittoScreenWithTopBar
-import com.sadellie.unitto.feature.datedifference.components.DateTimeResultBlock
-import com.sadellie.unitto.feature.datedifference.components.DateTimeSelectorBlock
-import java.time.LocalDateTime
-
-
-@Composable
-internal fun DateDifferenceRoute(
-    viewModel: DateDifferenceViewModel = hiltViewModel(),
-    navigateToMenu: () -> Unit,
-    navigateToSettings: () -> Unit,
-) {
-    val uiState = viewModel.uiState.collectAsStateWithLifecycle()
-    DateDifferenceScreen(
-        navigateToMenu = navigateToMenu,
-        navigateToSettings = navigateToSettings,
-        uiState = uiState.value,
-        setStartTime = viewModel::setStartTime,
-        setEndTime = viewModel::setEndTime,
-        setStartDate = viewModel::setStartDate,
-        setEndDate = viewModel::setEndDate,
-    )
-}
-
-@OptIn(ExperimentalLayoutApi::class)
-@Composable
-internal fun DateDifferenceScreen(
-    navigateToMenu: () -> Unit,
-    navigateToSettings: () -> Unit,
-    setStartTime: (Int, Int) -> Unit,
-    setEndTime: (Int, Int) -> Unit,
-    setStartDate: (LocalDateTime) -> Unit,
-    setEndDate: (LocalDateTime) -> Unit,
-    uiState: UIState,
-) {
-    var dialogState by remember { mutableStateOf(DialogState.NONE) }
-
-    UnittoScreenWithTopBar(
-        title = { Text(stringResource(R.string.date_difference)) },
-        navigationIcon = { MenuButton(navigateToMenu) },
-        actions = {
-            SettingsButton(navigateToSettings)
-        }
-    ) { paddingValues ->
-        FlowRow(
-            modifier = Modifier
-                .padding(paddingValues)
-                .padding(horizontal = 16.dp),
-            maxItemsInEachRow = 2,
-            verticalArrangement = Arrangement.spacedBy(16.dp),
-            horizontalArrangement = Arrangement.spacedBy(16.dp)
-        ) {
-            DateTimeSelectorBlock(
-                modifier = Modifier
-                    .weight(1f)
-                    .fillMaxWidth(),
-                title = stringResource(R.string.date_difference_start),
-                onClick = { dialogState = DialogState.FROM },
-                onTimeClick = { dialogState = DialogState.FROM_TIME },
-                onDateClick = { dialogState = DialogState.FROM_DATE },
-                dateTime = uiState.start
-            )
-
-            DateTimeSelectorBlock(
-                modifier = Modifier
-                    .weight(1f)
-                    .fillMaxWidth(),
-                title = stringResource(R.string.date_difference_end),
-                onClick = { dialogState = DialogState.TO },
-                onTimeClick = { dialogState = DialogState.TO_TIME },
-                onDateClick = { dialogState = DialogState.TO_DATE },
-                dateTime = uiState.end
-            )
-
-            AnimatedVisibility(
-                visible = uiState.result is DateDifference.Default,
-                enter = expandVertically(),
-                exit = shrinkVertically()
-            ) {
-                DateTimeResultBlock(
-                    modifier = Modifier
-                        .weight(2f)
-                        .fillMaxWidth(),
-                    dateDifference = uiState.result
-                )
-            }
-        }
-    }
-
-    fun resetDialog() {
-        dialogState = DialogState.NONE
-    }
-
-    when (dialogState) {
-        DialogState.FROM -> {
-            TimePickerDialog(
-                hour = uiState.start.hour,
-                minute = uiState.start.minute,
-                onDismiss = ::resetDialog,
-                onConfirm = { hour, minute ->
-                    setStartTime(hour, minute)
-                    dialogState = DialogState.FROM_DATE
-                },
-                confirmLabel = stringResource(R.string.next_label),
-            )
-        }
-
-        DialogState.FROM_TIME -> {
-            TimePickerDialog(
-                hour = uiState.start.hour,
-                minute = uiState.start.minute,
-                onDismiss = ::resetDialog,
-                onConfirm = { hour, minute ->
-                    setStartTime(hour, minute)
-                    resetDialog()
-                },
-            )
-        }
-
-        DialogState.FROM_DATE -> {
-            DatePickerDialog(
-                localDateTime = uiState.start,
-                onDismiss = ::resetDialog,
-                onConfirm = {
-                    setStartDate(it)
-                    resetDialog()
-                }
-            )
-        }
-
-        DialogState.TO -> {
-            TimePickerDialog(
-                hour = uiState.end.hour,
-                minute = uiState.end.minute,
-                onDismiss = ::resetDialog,
-                onConfirm = { hour, minute ->
-                    setEndTime(hour, minute)
-                    dialogState = DialogState.TO_DATE
-                },
-                confirmLabel = stringResource(R.string.next_label),
-            )
-        }
-
-        DialogState.TO_TIME -> {
-            TimePickerDialog(
-                hour = uiState.end.hour,
-                minute = uiState.end.minute,
-                onDismiss = ::resetDialog,
-                onConfirm = { hour, minute ->
-                    setEndTime(hour, minute)
-                    resetDialog()
-                },
-            )
-        }
-
-        DialogState.TO_DATE -> {
-            DatePickerDialog(
-                localDateTime = uiState.end,
-                onDismiss = ::resetDialog,
-                onConfirm = {
-                    setEndDate(it)
-                    resetDialog()
-                }
-            )
-        }
-
-        else -> {}
-    }
-}
-
-private enum class DialogState {
-    NONE, FROM, FROM_TIME, FROM_DATE, TO, TO_TIME, TO_DATE
-}
-
-@Preview
-@Composable
-private fun DateDifferenceScreenPreview() {
-    DateDifferenceScreen(
-        navigateToMenu = {},
-        navigateToSettings = {},
-        setStartTime = { _, _ -> },
-        setEndTime = { _, _ -> },
-        uiState = UIState(
-            result = DateDifference.Default(4, 1, 2, 3, 4)
-        ),
-        setStartDate = {},
-        setEndDate = {},
-    )
-}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/DateToolsScreen.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/DateToolsScreen.kt
@ -0,0 +1,117 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.navigationBarsPadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.pager.HorizontalPager
+import androidx.compose.foundation.pager.rememberPagerState
+import androidx.compose.material3.Tab
+import androidx.compose.material3.TabRow
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import com.sadellie.unitto.core.base.R
+import com.sadellie.unitto.core.ui.common.MenuButton
+import com.sadellie.unitto.core.ui.common.SettingsButton
+import com.sadellie.unitto.core.ui.common.UnittoScreenWithTopBar
+import com.sadellie.unitto.feature.datedifference.addsubtract.AddSubtractPage
+import com.sadellie.unitto.feature.datedifference.difference.DateDifferencePage
+import kotlinx.coroutines.launch
+
+@Composable
+internal fun DateToolsRoute(
+    navigateToMenu: () -> Unit,
+    navigateToSettings: () -> Unit,
+) {
+    DateToolsScreen(
+        navigateToMenu = navigateToMenu,
+        navigateToSettings = navigateToSettings,
+    )
+}
+
+@Composable
+internal fun DateToolsScreen(
+    navigateToMenu: () -> Unit,
+    navigateToSettings: () -> Unit,
+) {
+    val addSubtractLabel = "${stringResource(R.string.add)}/${stringResource(R.string.subtract)}"
+    val differenceLabel = stringResource(R.string.difference)
+
+    val allTabs = remember { mutableListOf(addSubtractLabel, differenceLabel) }
+    val pagerState = rememberPagerState { allTabs.size }
+    val coroutineScope = rememberCoroutineScope()
+
+    UnittoScreenWithTopBar(
+        modifier = Modifier
+            .navigationBarsPadding()
+            .imePadding(),
+        title = { Text(stringResource(R.string.date_calculator)) },
+        navigationIcon = { MenuButton(navigateToMenu) },
+        actions = {
+            SettingsButton(navigateToSettings)
+        },
+    ) { paddingValues ->
+        Column(
+            modifier = Modifier.padding(paddingValues),
+        ) {
+            TabRow(
+                selectedTabIndex = pagerState.currentPage,
+            ) {
+                allTabs.forEachIndexed { index, tab ->
+                    Tab(
+                        selected = index == pagerState.currentPage,
+                        onClick = {
+                            coroutineScope.launch {
+                                pagerState.animateScrollToPage(index)
+                            }
+                        },
+                        text = { Text(tab) }
+                    )
+                }
+            }
+
+            HorizontalPager(
+                state = pagerState,
+                verticalAlignment = Alignment.Top
+            ) { page ->
+                when (page) {
+                    0 -> AddSubtractPage()
+                    1 -> DateDifferencePage()
+                }
+            }
+        }
+    }
+}
+
+@Preview
+@Composable
+private fun DateDifferenceScreenPreview() {
+    DateToolsScreen(
+        navigateToMenu = {},
+        navigateToSettings = {},
+    )
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/ZonedDateTimeDifference.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/ZonedDateTimeDifference.kt
@ -18,10 +18,10 @@

 package com.sadellie.unitto.feature.datedifference

-import java.time.LocalDateTime
+import java.time.ZonedDateTime
 import java.time.temporal.ChronoUnit

-internal sealed class DateDifference(
+internal sealed class ZonedDateTimeDifference(
    open val years: Long = 0,
    open val months: Long = 0,
    open val days: Long = 0,
@ -34,7 +34,7 @@ internal sealed class DateDifference(
        override val days: Long = 0,
        override val hours: Long = 0,
        override val minutes: Long = 0,
-    ) : DateDifference(
+    ) : ZonedDateTimeDifference(
        years = years,
        months = months,
        days = days,
@ -42,15 +42,15 @@ internal sealed class DateDifference(
        minutes = minutes,
    )

-    object Zero : DateDifference()
+    object Zero : ZonedDateTimeDifference()
 }

 // https://stackoverflow.com/a/25760725
-internal infix operator fun LocalDateTime.minus(localDateTime: LocalDateTime): DateDifference {
-    if (this == localDateTime) return DateDifference.Zero
+internal infix operator fun ZonedDateTime.minus(localDateTime: ZonedDateTime): ZonedDateTimeDifference {
+    if (this == localDateTime) return ZonedDateTimeDifference.Zero

-    var fromDateTime: LocalDateTime = this
-    var toDateTime: LocalDateTime = localDateTime
+    var fromDateTime: ZonedDateTime = this
+    var toDateTime: ZonedDateTime = localDateTime

    // Swap to avoid negative
    if (this > localDateTime) {
@ -58,7 +58,7 @@ internal infix operator fun LocalDateTime.minus(localDateTime: LocalDateTime): D
        toDateTime = this
    }

-    var tempDateTime = LocalDateTime.from(fromDateTime)
+    var tempDateTime = ZonedDateTime.from(fromDateTime)

    val years = tempDateTime.until(toDateTime, ChronoUnit.YEARS)

@ -74,9 +74,9 @@ internal infix operator fun LocalDateTime.minus(localDateTime: LocalDateTime): D
    tempDateTime = tempDateTime.plusHours(hours)
    val minutes = tempDateTime.until(toDateTime, ChronoUnit.MINUTES)

-    if (listOf(years, months, days, hours, minutes).sum() == 0L) return DateDifference.Zero
+    if (listOf(years, months, days, hours, minutes).sum() == 0L) return ZonedDateTimeDifference.Zero

-    return DateDifference.Default(
+    return ZonedDateTimeDifference.Default(
        years = years, months = months, days = days, hours = hours, minutes = minutes
    )
 }
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractPage.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractPage.kt
@ -0,0 +1,241 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.addsubtract
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.provider.CalendarContract
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Event
+import androidx.compose.material.icons.outlined.Add
+import androidx.compose.material.icons.outlined.Remove
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SegmentedButton
+import androidx.compose.material3.SegmentedButtonDefaults
+import androidx.compose.material3.SingleChoiceSegmentedButtonRow
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.sadellie.unitto.core.base.R
+import com.sadellie.unitto.feature.datedifference.components.DateTimeDialogs
+import com.sadellie.unitto.feature.datedifference.components.DateTimeSelectorBlock
+import com.sadellie.unitto.feature.datedifference.components.DialogState
+import com.sadellie.unitto.feature.datedifference.components.TimeUnitTextField
+import java.time.ZonedDateTime
+
+@Composable
+internal fun AddSubtractPage(
+    viewModel: AddSubtractViewModel = hiltViewModel(),
+) {
+    val uiState = viewModel.uiState.collectAsStateWithLifecycle().value
+
+    AddSubtractView(
+        uiState = uiState,
+        updateStart = viewModel::updateStart,
+        updateYears = viewModel::updateYears,
+        updateMonths = viewModel::updateMonths,
+        updateDays = viewModel::updateDays,
+        updateHours = viewModel::updateHours,
+        updateMinutes = viewModel::updateMinutes,
+        updateAddition = viewModel::updateAddition
+    )
+}
+
+@SuppressLint("UnusedMaterial3ScaffoldPaddingParameter")
+@OptIn(ExperimentalLayoutApi::class)
+@Composable
+private fun AddSubtractView(
+    uiState: AddSubtractState,
+    updateStart: (ZonedDateTime) -> Unit,
+    updateYears: (String) -> Unit,
+    updateMonths: (String) -> Unit,
+    updateDays: (String) -> Unit,
+    updateHours: (String) -> Unit,
+    updateMinutes: (String) -> Unit,
+    updateAddition: (Boolean) -> Unit,
+) {
+    var dialogState by remember { mutableStateOf(DialogState.NONE) }
+    val mContext = LocalContext.current
+
+    Scaffold(
+        floatingActionButton = {
+            FloatingActionButton(onClick = { mContext.addEvent(uiState.start, uiState.result) }) {
+                Icon(
+                    imageVector = Icons.Default.Event,
+                    contentDescription = null,
+                )
+            }
+        }
+    ) {
+        LazyColumn(
+            modifier = Modifier.padding(start = 16.dp, end = 16.dp, top = 16.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+            contentPadding = PaddingValues(bottom = 88.dp)
+        ) {
+            item("dates") {
+                FlowRow(
+                    modifier = Modifier,
+                    maxItemsInEachRow = 2,
+                    verticalArrangement = Arrangement.spacedBy(16.dp),
+                    horizontalArrangement = Arrangement.spacedBy(16.dp)
+                ) {
+                    DateTimeSelectorBlock(
+                        modifier = Modifier
+                            .weight(1f)
+                            .fillMaxWidth(),
+                        title = stringResource(R.string.date_difference_start),
+                        dateTime = uiState.start,
+                        onLongClick = { updateStart(ZonedDateTime.now()) },
+                        onClick = { dialogState = DialogState.FROM },
+                        onTimeClick = { dialogState = DialogState.FROM_TIME },
+                        onDateClick = { dialogState = DialogState.FROM_DATE },
+                    )
+
+                    DateTimeSelectorBlock(
+                        modifier = Modifier
+                            .weight(1f)
+                            .fillMaxWidth(),
+                        title = stringResource(R.string.date_difference_end),
+                        dateTime = uiState.result,
+                    )
+                }
+            }
+
+            item("modes") {
+                SingleChoiceSegmentedButtonRow(
+                    modifier = Modifier
+                        .fillMaxWidth(),
+                ) {
+                    SegmentedButton(
+                        selected = uiState.addition,
+                        onClick = { updateAddition(true) },
+                        shape = SegmentedButtonDefaults.shape(position = 0, count = 2),
+                        icon = {}
+                    ) {
+                        Icon(Icons.Outlined.Add, null)
+                    }
+                    SegmentedButton(
+                        selected = !uiState.addition,
+                        onClick = { updateAddition(false) },
+                        shape = SegmentedButtonDefaults.shape(position = 1, count = 2),
+                        icon = {}
+                    ) {
+                        Icon(Icons.Outlined.Remove, null)
+                    }
+                }
+            }
+
+            item("textFields") {
+                Column {
+                    TimeUnitTextField(
+                        value = uiState.years,
+                        onValueChange = updateYears,
+                        label = stringResource(R.string.date_difference_years),
+                        formatterSymbols = uiState.formatterSymbols
+                    )
+                    TimeUnitTextField(
+                        value = uiState.months,
+                        onValueChange = updateMonths,
+                        label = stringResource(R.string.date_difference_months),
+                        formatterSymbols = uiState.formatterSymbols
+                    )
+                    TimeUnitTextField(
+                        value = uiState.days,
+                        onValueChange = updateDays,
+                        label = stringResource(R.string.date_difference_days),
+                        formatterSymbols = uiState.formatterSymbols
+                    )
+                    TimeUnitTextField(
+                        value = uiState.hours,
+                        onValueChange = updateHours,
+                        label = stringResource(R.string.date_difference_hours),
+                        formatterSymbols = uiState.formatterSymbols
+                    )
+                    TimeUnitTextField(
+                        value = uiState.minutes,
+                        onValueChange = updateMinutes,
+                        label = stringResource(R.string.date_difference_minutes),
+                        imeAction = ImeAction.Done,
+                        formatterSymbols = uiState.formatterSymbols
+                    )
+                }
+            }
+        }
+    }
+
+    DateTimeDialogs(
+        dialogState = dialogState,
+        updateDialogState = { dialogState = it },
+        date = uiState.start,
+        updateDate = updateStart,
+        bothState = DialogState.FROM,
+        timeState = DialogState.FROM_TIME,
+        dateState = DialogState.FROM_DATE,
+    )
+}
+
+private fun Context.addEvent(start: ZonedDateTime, end: ZonedDateTime) {
+    val startMillis: Long = start.toEpochSecond() * 1000
+    val endMillis: Long = end.toEpochSecond() * 1000
+    val intent = Intent(Intent.ACTION_INSERT)
+        .setData(CalendarContract.Events.CONTENT_URI)
+        .putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, startMillis)
+        .putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endMillis)
+        .putExtra(CalendarContract.Events.AVAILABILITY, CalendarContract.Events.AVAILABILITY_BUSY)
+
+    startActivity(intent)
+}
+
+@Preview
+@Composable
+fun AddSubtractViewPreview() {
+    AddSubtractView(
+        uiState = AddSubtractState(
+            years = "12"
+        ),
+        updateStart = {},
+        updateYears = {},
+        updateMonths = {},
+        updateDays = {},
+        updateHours = {},
+        updateMinutes = {},
+        updateAddition = {}
+    )
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractUIState.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractUIState.kt
@ -0,0 +1,34 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.addsubtract
+
+import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
+import java.time.ZonedDateTime
+
+internal data class AddSubtractState(
+    val start: ZonedDateTime = ZonedDateTime.now(),
+    val result: ZonedDateTime = ZonedDateTime.now(),
+    val years: String = "",
+    val months: String = "",
+    val days: String = "",
+    val hours: String = "",
+    val minutes: String = "",
+    val addition: Boolean = true,
+    val formatterSymbols: FormatterSymbols = FormatterSymbols.Spaces,
+)
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractViewModel.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/addsubtract/AddSubtractViewModel.kt
@ -0,0 +1,129 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.addsubtract
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.sadellie.unitto.core.ui.common.textfield.AllFormatterSymbols
+import com.sadellie.unitto.data.userprefs.UserPreferencesRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import java.time.ZonedDateTime
+import javax.inject.Inject
+
+@HiltViewModel
+internal class AddSubtractViewModel @Inject constructor(
+    userPreferencesRepository: UserPreferencesRepository
+) : ViewModel() {
+    private val _uiState = MutableStateFlow(AddSubtractState())
+
+    val uiState: StateFlow<AddSubtractState> = _uiState
+        .combine(userPreferencesRepository.allPreferencesFlow) { uiState, userPrefs ->
+            return@combine uiState.copy(
+                formatterSymbols = AllFormatterSymbols.getById(userPrefs.separator)
+            )
+        }
+        .onEach { updateResult() }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000L), AddSubtractState())
+
+    private fun updateResult() = viewModelScope.launch(Dispatchers.Default) {
+        // Gets canceled, works with latest _uiState only
+        _uiState.update { ui ->
+            val newResult = if (ui.addition) {
+                ui.start
+                    .plusYears(ui.years.ifEmpty { "0" }.toLong())
+                    .plusMonths(ui.months.ifEmpty { "0" }.toLong())
+                    .plusDays(ui.days.ifEmpty { "0" }.toLong())
+                    .plusHours(ui.hours.ifEmpty { "0" }.toLong())
+                    .plusMinutes(ui.minutes.ifEmpty { "0" }.toLong())
+            } else {
+                ui.start
+                    .minusYears(ui.years.ifEmpty { "0" }.toLong())
+                    .minusMonths(ui.months.ifEmpty { "0" }.toLong())
+                    .minusDays(ui.days.ifEmpty { "0" }.toLong())
+                    .minusHours(ui.hours.ifEmpty { "0" }.toLong())
+                    .minusMinutes(ui.minutes.ifEmpty { "0" }.toLong())
+            }
+            ui.copy(result = newResult)
+        }
+    }
+
+    fun updateStart(newValue: ZonedDateTime) = _uiState.update { it.copy(start = newValue) }
+
+    fun updateYears(newValue: String) = _uiState.update {
+        val years = when {
+            newValue.isEmpty() -> newValue
+            newValue.toLong() > 9_999L -> "9999"
+            else -> newValue
+        }
+
+        it.copy(years = years)
+    }
+
+    fun updateMonths(newValue: String) = _uiState.update {
+        val months = when {
+            newValue.isEmpty() -> newValue
+            newValue.toLong() > 9_999L -> "9999"
+            else -> newValue
+        }
+
+        it.copy(months = months)
+    }
+
+    fun updateDays(newValue: String) = _uiState.update {
+        val days = when {
+            newValue.isEmpty() -> newValue
+            newValue.toLong() > 99_999L -> "99999"
+            else -> newValue
+        }
+
+        it.copy(days = days)
+    }
+
+    fun updateHours(newValue: String) = _uiState.update {
+        val hours = when {
+            newValue.isEmpty() -> newValue
+            newValue.toLong() > 9_999_999L -> "9999999"
+            else -> newValue
+        }
+
+        it.copy(hours = hours)
+    }
+
+    fun updateMinutes(newValue: String) = _uiState.update {
+        val minutes = when {
+            newValue.isEmpty() -> newValue
+            newValue.toLong() > 99_999_999L -> "99999999"
+            else -> newValue
+        }
+
+        it.copy(minutes = minutes)
+    }
+
+    // BCE is not handled properly because who gives a shit...
+    fun updateAddition(newValue: Boolean) = _uiState.update { it.copy(addition = newValue) }
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeDialogs.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeDialogs.kt
@ -0,0 +1,79 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.components
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import com.sadellie.unitto.core.base.R
+import com.sadellie.unitto.core.ui.common.DatePickerDialog
+import com.sadellie.unitto.core.ui.common.TimePickerDialog
+import java.time.ZonedDateTime
+
+@Composable
+internal fun DateTimeDialogs(
+    dialogState: DialogState?,
+    updateDialogState: (DialogState) -> Unit,
+    date: ZonedDateTime,
+    updateDate: (ZonedDateTime) -> Unit,
+    bothState: DialogState,
+    timeState: DialogState,
+    dateState: DialogState,
+) {
+    when (dialogState) {
+        bothState -> {
+            TimePickerDialog(
+                hour = date.hour,
+                minute = date.minute,
+                onDismiss = { updateDialogState(DialogState.NONE) },
+                onConfirm = { hour, minute ->
+                    updateDate(date.withHour(hour).withMinute(minute))
+                    updateDialogState(dateState)
+                },
+                confirmLabel = stringResource(R.string.next_label),
+            )
+        }
+
+        timeState -> {
+            TimePickerDialog(
+                hour = date.hour,
+                minute = date.minute,
+                onDismiss = { updateDialogState(DialogState.NONE) },
+                onConfirm = { hour, minute ->
+                    updateDate(date.withHour(hour).withMinute(minute))
+                    updateDialogState(DialogState.NONE)
+                },
+            )
+        }
+
+        dateState -> {
+            DatePickerDialog(
+                localDateTime = date,
+                onDismiss = { updateDialogState(DialogState.NONE) },
+                onConfirm = {
+                    updateDate(it)
+                    updateDialogState(DialogState.NONE)
+                }
+            )
+        }
+
+        else -> {}
+    }
+}
+
+internal enum class DialogState { NONE, FROM, FROM_TIME, FROM_DATE, TO, TO_TIME, TO_DATE }
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeResultBlock.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeResultBlock.kt
@ -47,20 +47,20 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.sadellie.unitto.core.base.R
 import com.sadellie.unitto.core.ui.common.squashable
-import com.sadellie.unitto.feature.datedifference.DateDifference
+import com.sadellie.unitto.feature.datedifference.ZonedDateTimeDifference

@Composable
 internal fun DateTimeResultBlock(
    modifier: Modifier = Modifier,
-    dateDifference: DateDifference
+    zonedDateTimeDifference: ZonedDateTimeDifference
 ) {
    val clipboardManager = LocalClipboardManager.current

-    val years = dateDifference.years.formatDateTimeValue(R.string.date_difference_years)
-    val months = dateDifference.months.formatDateTimeValue(R.string.date_difference_months)
-    val days = dateDifference.days.formatDateTimeValue(R.string.date_difference_days)
-    val hours = dateDifference.hours.formatDateTimeValue(R.string.date_difference_hours)
-    val minutes = dateDifference.minutes.formatDateTimeValue(R.string.date_difference_minutes)
+    val years = zonedDateTimeDifference.years.formatDateTimeValue(R.string.date_difference_years)
+    val months = zonedDateTimeDifference.months.formatDateTimeValue(R.string.date_difference_months)
+    val days = zonedDateTimeDifference.days.formatDateTimeValue(R.string.date_difference_days)
+    val hours = zonedDateTimeDifference.hours.formatDateTimeValue(R.string.date_difference_hours)
+    val minutes = zonedDateTimeDifference.minutes.formatDateTimeValue(R.string.date_difference_minutes)

    val texts = listOf(years, months, days, hours, minutes)

@ -117,10 +117,10 @@ private fun Long.formatDateTimeValue(@StringRes id: Int): String {

@Preview
@Composable
-private fun PreviewCard() {
+private fun DateTimeResultBlockPreview() {
    DateTimeResultBlock(
        modifier = Modifier,
-        dateDifference = DateDifference.Default(
+        zonedDateTimeDifference = ZonedDateTimeDifference.Default(
            months = 1,
            days = 2,
            hours = 3,
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeSelectorBlock.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/DateTimeSelectorBlock.kt
@ -24,6 +24,7 @@ import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
 import androidx.compose.material.ripple.rememberRipple
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
@ -32,24 +33,27 @@ import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.sadellie.unitto.core.ui.common.squashable
-import java.time.LocalDateTime
+import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter

@Composable
 internal fun DateTimeSelectorBlock(
-    modifier: Modifier,
+    modifier: Modifier = Modifier,
    title: String,
-    dateTime: LocalDateTime,
-    onClick: () -> Unit,
-    onTimeClick: () -> Unit,
-    onDateClick: () -> Unit,
+    dateTime: ZonedDateTime,
+    onClick: () -> Unit = {},
+    onTimeClick: () -> Unit = {},
+    onDateClick: () -> Unit = {},
+    onLongClick: () -> Unit = {},
 ) {
    Column(
        modifier = modifier
            .squashable(
                onClick = onClick,
+                onLongClick = onLongClick,
                interactionSource = remember { MutableInteractionSource() },
                cornerRadiusRange = 8.dp..32.dp
            )
@ -107,3 +111,13 @@ private val time24Formatter by lazy { DateTimeFormatter.ofPattern("HH:mm") }
 private val time12Formatter by lazy { DateTimeFormatter.ofPattern("hh:mm") }
 private val dateFormatter by lazy { DateTimeFormatter.ofPattern("EEE, MMM d, y") }
 private val mTimeFormatter by lazy { DateTimeFormatter.ofPattern("a") }
+
+@Preview
+@Composable
+fun DateTimeSelectorBlockPreview() {
+    DateTimeSelectorBlock(
+        title = "End",
+        dateTime = ZonedDateTime.now(),
+        modifier = Modifier.width(224.dp)
+    )
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/TimeUnitTextField.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/components/TimeUnitTextField.kt
@ -0,0 +1,73 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.components
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.scaleIn
+import androidx.compose.animation.scaleOut
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Clear
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
+import com.sadellie.unitto.core.ui.common.textfield.ExpressionTransformer
+import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
+
+@Composable
+internal fun TimeUnitTextField(
+    value: String,
+    onValueChange: (String) -> Unit,
+    label: String,
+    imeAction: ImeAction = ImeAction.Next,
+    formatterSymbols: FormatterSymbols
+) {
+    OutlinedTextField(
+        modifier = Modifier.fillMaxWidth(),
+        value = value,
+        onValueChange = { newValue ->
+            onValueChange(newValue.filter { it.isDigit() })
+        },
+        label = { Text(label, color = MaterialTheme.colorScheme.onSurfaceVariant) },
+        trailingIcon = {
+            AnimatedVisibility(
+                visible = value.isNotBlank(),
+                enter = scaleIn(),
+                exit = scaleOut()
+            ) {
+                IconButton(onClick = { onValueChange("") }) {
+                    Icon(Icons.Outlined.Clear, null)
+                }
+            }
+        },
+        keyboardOptions = KeyboardOptions(
+            autoCorrect = false,
+            keyboardType = KeyboardType.Decimal,
+            imeAction = imeAction
+        ),
+        visualTransformation = ExpressionTransformer(formatterSymbols)
+    )
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DateDifferencePage.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DateDifferencePage.kt
@ -0,0 +1,145 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.datedifference.difference
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.expandVertically
+import androidx.compose.animation.shrinkVertically
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.sadellie.unitto.core.base.R
+import com.sadellie.unitto.feature.datedifference.ZonedDateTimeDifference
+import com.sadellie.unitto.feature.datedifference.components.DateTimeDialogs
+import com.sadellie.unitto.feature.datedifference.components.DateTimeResultBlock
+import com.sadellie.unitto.feature.datedifference.components.DateTimeSelectorBlock
+import com.sadellie.unitto.feature.datedifference.components.DialogState
+import java.time.ZonedDateTime
+
+@Composable
+internal fun DateDifferencePage(
+    viewModel: DateDifferenceViewModel = hiltViewModel(),
+) {
+    val uiState = viewModel.uiState.collectAsStateWithLifecycle()
+
+    DateDifferenceView(
+        uiState = uiState.value,
+        setStartDate = viewModel::setStartDate,
+        setEndDate = viewModel::setEndDate
+    )
+}
+
+@Composable
+@OptIn(ExperimentalLayoutApi::class)
+private fun DateDifferenceView(
+    uiState: DifferenceUIState,
+    setStartDate: (ZonedDateTime) -> Unit,
+    setEndDate: (ZonedDateTime) -> Unit,
+) {
+    var dialogState by remember { mutableStateOf(DialogState.NONE) }
+
+    FlowRow(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(16.dp),
+        maxItemsInEachRow = 2,
+        verticalArrangement = Arrangement.spacedBy(16.dp),
+        horizontalArrangement = Arrangement.spacedBy(16.dp)
+    ) {
+        DateTimeSelectorBlock(
+            modifier = Modifier
+                .weight(1f)
+                .fillMaxWidth(),
+            title = stringResource(R.string.date_difference_start),
+            dateTime = uiState.start,
+            onClick = { dialogState = DialogState.FROM },
+            onTimeClick = { dialogState = DialogState.FROM_TIME },
+            onDateClick = { dialogState = DialogState.FROM_DATE },
+        )
+
+        DateTimeSelectorBlock(
+            modifier = Modifier
+                .weight(1f)
+                .fillMaxWidth(),
+            title = stringResource(R.string.date_difference_end),
+            dateTime = uiState.end,
+            onClick = { dialogState = DialogState.TO },
+            onTimeClick = { dialogState = DialogState.TO_TIME },
+            onDateClick = { dialogState = DialogState.TO_DATE },
+        )
+
+        AnimatedVisibility(
+            visible = uiState.result is ZonedDateTimeDifference.Default,
+            enter = expandVertically(),
+            exit = shrinkVertically()
+        ) {
+            DateTimeResultBlock(
+                modifier = Modifier
+                    .weight(2f)
+                    .fillMaxWidth(),
+                zonedDateTimeDifference = uiState.result,
+            )
+        }
+    }
+
+    DateTimeDialogs(
+        dialogState = dialogState,
+        updateDialogState = { dialogState = it },
+        date = uiState.start,
+        updateDate = setStartDate,
+        bothState = DialogState.FROM,
+        timeState = DialogState.FROM_TIME,
+        dateState = DialogState.FROM_DATE,
+    )
+
+    DateTimeDialogs(
+        dialogState = dialogState,
+        updateDialogState = { dialogState = it },
+        date = uiState.end,
+        updateDate = setEndDate,
+        bothState = DialogState.TO,
+        timeState = DialogState.TO_TIME,
+        dateState = DialogState.TO_DATE,
+    )
+}
+
+
+@Preview
+@Composable
+fun DateDifferenceViewPreview() {
+    DateDifferenceView(
+        uiState = DifferenceUIState(),
+        setStartDate = {},
+        setEndDate = {},
+    )
+}
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DateDifferenceViewModel.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DateDifferenceViewModel.kt
@ -16,10 +16,12 @@
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

-package com.sadellie.unitto.feature.datedifference
+package com.sadellie.unitto.feature.datedifference.difference

 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.sadellie.unitto.feature.datedifference.ZonedDateTimeDifference
+import com.sadellie.unitto.feature.datedifference.minus
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
@ -30,29 +32,25 @@ import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
-import java.time.LocalDateTime
+import java.time.ZonedDateTime
 import javax.inject.Inject

@HiltViewModel
 internal class DateDifferenceViewModel @Inject constructor() : ViewModel() {
-    private val _start = MutableStateFlow(LocalDateTime.now())
-    private val _end = MutableStateFlow(LocalDateTime.now())
-    private val _result = MutableStateFlow<DateDifference>(DateDifference.Zero)
+    private val _start = MutableStateFlow(ZonedDateTime.now())
+    private val _end = MutableStateFlow(ZonedDateTime.now())
+    private val _result = MutableStateFlow<ZonedDateTimeDifference>(ZonedDateTimeDifference.Zero)

    val uiState = combine(_start, _end, _result) { start, end, result ->
-        return@combine UIState(start, end, result)
+        return@combine DifferenceUIState(start, end, result)
    }
        .stateIn(
-            viewModelScope, SharingStarted.WhileSubscribed(5000L), UIState()
+            viewModelScope, SharingStarted.WhileSubscribed(5000L), DifferenceUIState()
        )

-    fun setStartTime(hour: Int, minute: Int) = _start.update { it.withHour(hour).withMinute(minute) }
+    fun setStartDate(dateTime: ZonedDateTime) = _start.update { dateTime }

-    fun setEndTime(hour: Int, minute: Int) = _end.update { it.withHour(hour).withMinute(minute) }
-
-    fun setStartDate(dateTime: LocalDateTime) = _start.update { dateTime }
-
-    fun setEndDate(dateTime: LocalDateTime) = _end.update { dateTime }
+    fun setEndDate(dateTime: ZonedDateTime) = _end.update { dateTime }

    init {
        viewModelScope.launch(Dispatchers.Default) {
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DifferenceUIState.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/difference/DifferenceUIState.kt
@ -16,12 +16,13 @@
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

-package com.sadellie.unitto.feature.datedifference
+package com.sadellie.unitto.feature.datedifference.difference

-import java.time.LocalDateTime
+import com.sadellie.unitto.feature.datedifference.ZonedDateTimeDifference
+import java.time.ZonedDateTime

-internal data class UIState(
-    val start: LocalDateTime = LocalDateTime.now(),
-    val end: LocalDateTime = LocalDateTime.now(),
-    val result: DateDifference = DateDifference.Zero
+internal data class DifferenceUIState(
+    val start: ZonedDateTime = ZonedDateTime.now(),
+    val end: ZonedDateTime = ZonedDateTime.now(),
+    val result: ZonedDateTimeDifference = ZonedDateTimeDifference.Zero
 )
--- a/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/navigation/DateDifferenceNavigation.kt
+++ b/feature/datedifference/src/main/java/com/sadellie/unitto/feature/datedifference/navigation/DateDifferenceNavigation.kt
@ -22,7 +22,7 @@ import androidx.navigation.NavGraphBuilder
 import androidx.navigation.compose.composable
 import androidx.navigation.navDeepLink
 import com.sadellie.unitto.core.base.TopLevelDestinations
-import com.sadellie.unitto.feature.datedifference.DateDifferenceRoute
+import com.sadellie.unitto.feature.datedifference.DateToolsRoute

 private val dateDifferenceRoute: String by lazy { TopLevelDestinations.DateDifference.route }

@ -36,7 +36,7 @@ fun NavGraphBuilder.dateDifferenceScreen(
            navDeepLink { uriPattern = "app://com.sadellie.unitto/$dateDifferenceRoute" }
        )
    ) {
-        DateDifferenceRoute(
+        DateToolsRoute(
            navigateToMenu = navigateToMenu,
            navigateToSettings = navigateToSettings
        )
--- a/feature/datedifference/src/test/java/com/sadellie/unitto/feature/datedifference/ZonedDateTimeDifferenceKtTest.kt
+++ b/feature/datedifference/src/test/java/com/sadellie/unitto/feature/datedifference/ZonedDateTimeDifferenceKtTest.kt
@ -20,32 +20,32 @@ package com.sadellie.unitto.feature.datedifference

 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
-import java.time.LocalDateTime
+import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter

-class DateDifferenceKtTest {
+class ZonedDateTimeDifferenceKtTest {
    private val fromatt: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm")
-    private val `may 1 2023`: LocalDateTime = LocalDateTime.parse("2023-05-01 12:00", fromatt)
-    private val `may 2 2023`: LocalDateTime = LocalDateTime.parse("2023-05-02 12:00", fromatt)
-    private val `june 1 2023`: LocalDateTime = LocalDateTime.parse("2023-06-01 12:00", fromatt)
+    private val `may 1 2023`: ZonedDateTime = ZonedDateTime.parse("2023-05-01 12:00", fromatt)
+    private val `may 2 2023`: ZonedDateTime = ZonedDateTime.parse("2023-05-02 12:00", fromatt)
+    private val `june 1 2023`: ZonedDateTime = ZonedDateTime.parse("2023-06-01 12:00", fromatt)

    @Test
    fun `same dates`() {
-        assertEquals(DateDifference.Zero, `may 1 2023` - `may 1 2023`)
+        assertEquals(ZonedDateTimeDifference.Zero, `may 1 2023` - `may 1 2023`)
    }

    @Test
    fun `positive difference dates one day`() {
-        assertEquals(DateDifference.Default(days = 1), `may 1 2023` - `may 2 2023`)
+        assertEquals(ZonedDateTimeDifference.Default(days = 1), `may 1 2023` - `may 2 2023`)
    }

    @Test
    fun `positive difference dates one minth`() {
-        assertEquals(DateDifference.Default(months = 1), `may 1 2023` - `june 1 2023`)
+        assertEquals(ZonedDateTimeDifference.Default(months = 1), `may 1 2023` - `june 1 2023`)
    }

    @Test
    fun `negative difference dates one day`() {
-        assertEquals(DateDifference.Default(days = 1), `may 2 2023` - `may 1 2023`)
+        assertEquals(ZonedDateTimeDifference.Default(days = 1), `may 2 2023` - `may 1 2023`)
    }
 }