Fix that an incorrect day would be selected in MaterialDatePicker (#1723)

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceFragment.kt

@@ -14,8 +14,6 @@ import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.view.ActionMode
 import androidx.core.view.isVisible
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Attendance
@@ -27,12 +25,10 @@ import io.github.wulkanowy.ui.modules.main.MainActivity
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.ui.modules.message.send.SendMessageActivity
 import io.github.wulkanowy.ui.widgets.DividerItemDecoration
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.dpToPx
 import io.github.wulkanowy.utils.firstSchoolDayInSchoolYear
 import io.github.wulkanowy.utils.getThemeAttrColor
-import io.github.wulkanowy.utils.toLocalDateTime
+import io.github.wulkanowy.utils.openMaterialDatePicker
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -224,29 +220,15 @@ class AttendanceFragment : BaseFragment<FragmentAttendanceBinding>(R.layout.frag
         (activity as? MainActivity)?.showDialogFragment(AttendanceDialog.newInstance(lesson))
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
-        val baseDate = currentDate.firstSchoolDayInSchoolYear
+        openMaterialDatePicker(
-        val rangeStart = baseDate.toTimestamp()
+            selected = selectedDate,
-        val rangeEnd = LocalDate.now().plusWeeks(1).toTimestamp()
+            rangeStart = selectedDate.firstSchoolDayInSchoolYear,
-
+            rangeEnd = LocalDate.now().plusWeeks(1),
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+            onDateSelected = {
-            setValidator(SchoolDaysValidator(rangeStart, rangeEnd))
+                presenter.onDateSet(it.year, it.monthValue, it.dayOfMonth)
-            setStart(rangeStart)
+            }
-            setEnd(rangeEnd)
+        )
-        }
-        val datePicker = MaterialDatePicker.Builder.datePicker()
-            .setCalendarConstraints(constraintsBuilder.build())
-            .setSelection(currentDate.toTimestamp())
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime()
-            presenter.onDateSet(date.year, date.monthValue, date.dayOfMonth)
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun showExcuseDialog() {

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceView.kt

@@ -48,7 +48,7 @@ interface AttendanceView : BaseView {
 
     fun showAttendanceDialog(lesson: Attendance)
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 
     fun showExcuseDialog()
 

app/src/main/java/io/github/wulkanowy/ui/modules/homework/add/HomeworkAddDialog.kt

@@ -5,17 +5,13 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.core.widget.doOnTextChanged
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.databinding.DialogHomeworkAddBinding
 import io.github.wulkanowy.ui.base.BaseDialogFragment
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.lastSchoolDayInSchoolYear
+import io.github.wulkanowy.utils.openMaterialDatePicker
 import io.github.wulkanowy.utils.toFormattedString
-import io.github.wulkanowy.utils.toLocalDateTime
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -25,6 +21,7 @@ class HomeworkAddDialog : BaseDialogFragment<DialogHomeworkAddBinding>(), Homewo
     @Inject
     lateinit var presenter: HomeworkAddPresenter
 
+    // todo: move it to presenter
     private var date: LocalDate? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -99,27 +96,16 @@ class HomeworkAddDialog : BaseDialogFragment<DialogHomeworkAddBinding>(), Homewo
         dismiss()
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
-        val rangeStart = LocalDate.now().toTimestamp()
+        openMaterialDatePicker(
-        val rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear.toTimestamp()
+            selected = selectedDate,
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+            rangeStart = LocalDate.now(),
-            setStart(rangeStart)
+            rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear,
-            setEnd(rangeEnd)
+            onDateSelected = {
-            setValidator(SchoolDaysValidator(rangeStart, rangeEnd))
+                date = it
-        }
+                binding.homeworkDialogDate.editText?.setText(date!!.toFormattedString())
-        val datePicker = MaterialDatePicker.Builder.datePicker()
+            }
-            .setCalendarConstraints(constraintsBuilder.build())
+        )
-            .setSelection(currentDate.toTimestamp())
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            date = it.toLocalDateTime().toLocalDate()
-            binding.homeworkDialogDate.editText?.setText(date!!.toFormattedString())
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(this.parentFragmentManager, null)
-        }
     }
 
     override fun onDestroyView() {

app/src/main/java/io/github/wulkanowy/ui/modules/homework/add/HomeworkAddView.kt

@@ -17,5 +17,5 @@ interface HomeworkAddView : BaseView {
 
     fun closeDialog()
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 }

app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/history/LuckyNumberHistoryFragment.kt

@@ -5,8 +5,6 @@ import android.view.View
 import android.view.View.GONE
 import android.view.View.VISIBLE
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.LuckyNumber
@@ -14,11 +12,9 @@ import io.github.wulkanowy.databinding.FragmentLuckyNumberHistoryBinding
 import io.github.wulkanowy.ui.base.BaseFragment
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.ui.widgets.DividerItemDecoration
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.dpToPx
 import io.github.wulkanowy.utils.firstSchoolDayInSchoolYear
-import io.github.wulkanowy.utils.toLocalDateTime
+import io.github.wulkanowy.utils.openMaterialDatePicker
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -111,29 +107,15 @@ class LuckyNumberHistoryFragment :
         binding.luckyNumberHistoryNextButton.visibility = if (show) VISIBLE else View.INVISIBLE
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
-        val baseDate = currentDate.firstSchoolDayInSchoolYear
+        openMaterialDatePicker(
-        val rangeStart = baseDate.toTimestamp()
+            selected = selectedDate,
-        val rangeEnd = LocalDate.now().plusWeeks(1).toTimestamp()
+            rangeStart = selectedDate.firstSchoolDayInSchoolYear,
-
+            rangeEnd = LocalDate.now().plusWeeks(1),
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+            onDateSelected = {
-            setValidator(SchoolDaysValidator(rangeStart, rangeEnd))
+                presenter.onDateSet(it.year, it.monthValue, it.dayOfMonth)
-            setStart(rangeStart)
+            }
-            setEnd(rangeEnd)
+        )
-        }
-        val datePicker = MaterialDatePicker.Builder.datePicker()
-            .setCalendarConstraints(constraintsBuilder.build())
-            .setSelection(currentDate.toTimestamp())
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime()
-            presenter.onDateSet(date.year, date.monthValue, date.dayOfMonth)
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun showContent(show: Boolean) {

app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/history/LuckyNumberHistoryView.kt

@@ -28,7 +28,7 @@ interface LuckyNumberHistoryView : BaseView {
 
     fun showNextButton(show: Boolean)
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 
     fun showContent(show: Boolean)
 

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableFragment.kt

@@ -9,8 +9,6 @@ import android.view.View.GONE
 import android.view.View.VISIBLE
 import androidx.core.text.parseAsHtml
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Timetable
@@ -22,13 +20,11 @@ import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.ui.modules.timetable.additional.AdditionalLessonsFragment
 import io.github.wulkanowy.ui.modules.timetable.completed.CompletedLessonsFragment
 import io.github.wulkanowy.ui.widgets.DividerItemDecoration
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.dpToPx
 import io.github.wulkanowy.utils.firstSchoolDayInSchoolYear
 import io.github.wulkanowy.utils.getThemeAttrColor
 import io.github.wulkanowy.utils.lastSchoolDayInSchoolYear
-import io.github.wulkanowy.utils.toLocalDateTime
+import io.github.wulkanowy.utils.openMaterialDatePicker
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -193,29 +189,15 @@ class TimetableFragment : BaseFragment<FragmentTimetableBinding>(R.layout.fragme
         (activity as? MainActivity)?.showDialogFragment(TimetableDialog.newInstance(lesson))
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
-        val baseDate = currentDate.firstSchoolDayInSchoolYear
+        openMaterialDatePicker(
-        val rangeStart = baseDate.toTimestamp()
+            selected = selectedDate,
-        val rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear.toTimestamp()
+            rangeStart = selectedDate.firstSchoolDayInSchoolYear,
-
+            rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear,
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+            onDateSelected = {
-            setValidator(SchoolDaysValidator(rangeStart, rangeEnd))
+                presenter.onDateSet(it.year, it.monthValue, it.dayOfMonth)
-            setStart(rangeStart)
+            }
-            setEnd(rangeEnd)
+        )
-        }
-        val datePicker = MaterialDatePicker.Builder.datePicker()
-            .setCalendarConstraints(constraintsBuilder.build())
-            .setSelection(currentDate.toTimestamp())
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime()
-            presenter.onDateSet(date.year, date.monthValue, date.dayOfMonth)
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun openAdditionalLessonsView() {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableView.kt

@@ -48,7 +48,7 @@ interface TimetableView : BaseView {
 
     fun showTimetableDialog(lesson: Timetable)
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 
     fun popView()
 

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/additional/AdditionalLessonsFragment.kt

@@ -4,8 +4,6 @@ import android.os.Bundle
 import android.view.View
 import androidx.appcompat.app.AlertDialog
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.TimetableAdditional
@@ -15,13 +13,11 @@ import io.github.wulkanowy.ui.modules.main.MainActivity
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.ui.modules.timetable.additional.add.AdditionalLessonAddDialog
 import io.github.wulkanowy.ui.widgets.DividerItemDecoration
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.dpToPx
 import io.github.wulkanowy.utils.firstSchoolDayInSchoolYear
 import io.github.wulkanowy.utils.getThemeAttrColor
 import io.github.wulkanowy.utils.lastSchoolDayInSchoolYear
-import io.github.wulkanowy.utils.toLocalDateTime
+import io.github.wulkanowy.utils.openMaterialDatePicker
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -144,29 +140,17 @@ class AdditionalLessonsFragment :
         (activity as? MainActivity)?.showDialogFragment(AdditionalLessonAddDialog.newInstance())
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
         val now = LocalDate.now()
-        val startOfSchoolYear = now.firstSchoolDayInSchoolYear.toTimestamp()
-        val endOfSchoolYear = now.lastSchoolDayInSchoolYear.toTimestamp()
 
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+        openMaterialDatePicker(
-            setValidator(SchoolDaysValidator(startOfSchoolYear, endOfSchoolYear))
+            selected = selectedDate,
-            setStart(startOfSchoolYear)
+            rangeStart = now.firstSchoolDayInSchoolYear,
-            setEnd(endOfSchoolYear)
+            rangeEnd = now.lastSchoolDayInSchoolYear,
-        }
+            onDateSelected = {
-        val datePicker = MaterialDatePicker.Builder.datePicker()
+                presenter.onDateSet(it.year, it.monthValue, it.dayOfMonth)
-            .setCalendarConstraints(constraintsBuilder.build())
+            }
-            .setSelection(currentDate.toTimestamp())
+        )
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime()
-            presenter.onDateSet(date.year, date.monthValue, date.dayOfMonth)
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun showDeleteLessonDialog(timetableAdditional: TimetableAdditional) {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/additional/AdditionalLessonsView.kt

@@ -34,7 +34,7 @@ interface AdditionalLessonsView : BaseView {
 
     fun showNextButton(show: Boolean)
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 
     fun showAddAdditionalLessonDialog()
 

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/additional/add/AdditionalLessonAddDialog.kt

@@ -5,19 +5,15 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.core.widget.doOnTextChanged
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import com.google.android.material.timepicker.MaterialTimePicker
 import com.google.android.material.timepicker.TimeFormat
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.databinding.DialogAdditionalAddBinding
 import io.github.wulkanowy.ui.base.BaseDialogFragment
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.lastSchoolDayInSchoolYear
+import io.github.wulkanowy.utils.openMaterialDatePicker
 import io.github.wulkanowy.utils.toFormattedString
-import io.github.wulkanowy.utils.toLocalDateTime
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import java.time.LocalTime
 import javax.inject.Inject
@@ -128,27 +124,15 @@ class AdditionalLessonAddDialog : BaseDialogFragment<DialogAdditionalAddBinding>
     }
 
     override fun showDatePickerDialog(selectedDate: LocalDate) {
-        val rangeStart = LocalDate.now().toTimestamp()
+        openMaterialDatePicker(
-        val rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear.toTimestamp()
+            selected = selectedDate,
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+            rangeStart = LocalDate.now(),
-            setStart(rangeStart)
+            rangeEnd = LocalDate.now().lastSchoolDayInSchoolYear,
-            setEnd(rangeEnd)
+            onDateSelected = {
-            setValidator(SchoolDaysValidator(rangeStart, rangeEnd))
+                presenter.onDateSelected(it)
-        }
+                binding.additionalLessonDialogDateEdit.setText(it.toFormattedString())
-        val datePicker = MaterialDatePicker.Builder.datePicker()
+            }
-            .setCalendarConstraints(constraintsBuilder.build())
+        )
-            .setSelection(selectedDate.toTimestamp())
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime().toLocalDate()
-            presenter.onDateSelected(date)
-            binding.additionalLessonDialogDateEdit.setText(date.toFormattedString())
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun showStartTimePickerDialog(selectedTime: LocalTime) {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsFragment.kt

@@ -6,8 +6,6 @@ import android.view.View.GONE
 import android.view.View.INVISIBLE
 import android.view.View.VISIBLE
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.google.android.material.datepicker.CalendarConstraints
-import com.google.android.material.datepicker.MaterialDatePicker
 import dagger.hilt.android.AndroidEntryPoint
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.CompletedLesson
@@ -16,14 +14,12 @@ import io.github.wulkanowy.ui.base.BaseFragment
 import io.github.wulkanowy.ui.modules.main.MainActivity
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.ui.widgets.DividerItemDecoration
-import io.github.wulkanowy.utils.SchoolDaysValidator
 import io.github.wulkanowy.utils.dpToPx
 import io.github.wulkanowy.utils.firstSchoolDayInSchoolYear
 import io.github.wulkanowy.utils.getCompatDrawable
 import io.github.wulkanowy.utils.getThemeAttrColor
 import io.github.wulkanowy.utils.lastSchoolDayInSchoolYear
-import io.github.wulkanowy.utils.toLocalDateTime
+import io.github.wulkanowy.utils.openMaterialDatePicker
-import io.github.wulkanowy.utils.toTimestamp
 import java.time.LocalDate
 import javax.inject.Inject
 
@@ -150,29 +146,17 @@ class CompletedLessonsFragment :
         )
     }
 
-    override fun showDatePickerDialog(currentDate: LocalDate) {
+    override fun showDatePickerDialog(selectedDate: LocalDate) {
         val now = LocalDate.now()
-        val startOfSchoolYear = now.firstSchoolDayInSchoolYear.toTimestamp()
-        val endOfSchoolYear = now.lastSchoolDayInSchoolYear.toTimestamp()
 
-        val constraintsBuilder = CalendarConstraints.Builder().apply {
+        openMaterialDatePicker(
-            setValidator(SchoolDaysValidator(startOfSchoolYear, endOfSchoolYear))
+            selected = selectedDate,
-            setStart(startOfSchoolYear)
+            rangeStart = now.firstSchoolDayInSchoolYear,
-            setEnd(endOfSchoolYear)
+            rangeEnd = now.lastSchoolDayInSchoolYear,
-        }
+            onDateSelected = {
-        val datePicker = MaterialDatePicker.Builder.datePicker()
+                presenter.onDateSet(it.year, it.monthValue, it.dayOfMonth)
-            .setCalendarConstraints(constraintsBuilder.build())
+            }
-            .setSelection(currentDate.toTimestamp())
+        )
-            .build()
-
-        datePicker.addOnPositiveButtonClickListener {
-            val date = it.toLocalDateTime()
-            presenter.onDateSet(date.year, date.monthValue, date.dayOfMonth)
-        }
-
-        if (!parentFragmentManager.isStateSaved) {
-            datePicker.show(parentFragmentManager, null)
-        }
     }
 
     override fun onSaveInstanceState(outState: Bundle) {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsView.kt

@@ -38,5 +38,5 @@ interface CompletedLessonsView : BaseView {
 
     fun showCompletedLessonDialog(completedLesson: CompletedLesson)
 
-    fun showDatePickerDialog(currentDate: LocalDate)
+    fun showDatePickerDialog(selectedDate: LocalDate)
 }

app/src/main/java/io/github/wulkanowy/utils/MaterialDatePickerUtils.kt

@@ -0,0 +1,51 @@
+package io.github.wulkanowy.utils
+
+import androidx.fragment.app.Fragment
+import com.google.android.material.datepicker.CalendarConstraints
+import com.google.android.material.datepicker.MaterialDatePicker
+import kotlinx.parcelize.Parcelize
+import java.time.LocalDate
+import java.time.ZoneOffset
+import java.time.temporal.ChronoUnit
+
+fun Fragment.openMaterialDatePicker(
+    selected: LocalDate,
+    rangeStart: LocalDate,
+    rangeEnd: LocalDate,
+    onDateSelected: (LocalDate) -> Unit,
+) {
+    val constraintsBuilder = CalendarConstraints.Builder().apply {
+        setValidator(CalendarDayRangeValidator(rangeStart, rangeEnd))
+        setStart(rangeStart.toTimestamp(ZoneOffset.UTC))
+        setEnd(rangeEnd.toTimestamp(ZoneOffset.UTC))
+    }
+
+    val datePicker = MaterialDatePicker.Builder.datePicker()
+        .setCalendarConstraints(constraintsBuilder.build())
+        .setSelection(selected.toTimestamp(ZoneOffset.UTC))
+        .build()
+
+    datePicker.addOnPositiveButtonClickListener {
+        val date = it.toLocalDateTime(ZoneOffset.UTC).toLocalDate()
+        onDateSelected(date)
+    }
+
+    if (!parentFragmentManager.isStateSaved) {
+        datePicker.show(parentFragmentManager, null)
+    }
+}
+
+@Parcelize
+private class CalendarDayRangeValidator(
+    val start: LocalDate,
+    val end: LocalDate,
+) : CalendarConstraints.DateValidator {
+
+    override fun isValid(dateLong: Long): Boolean {
+        val date = dateLong.toLocalDateTime().toLocalDate()
+        val daysUntilEnd = date.until(end, ChronoUnit.DAYS)
+        val daysUntilStart = date.until(start, ChronoUnit.DAYS)
+
+        return daysUntilStart <= 0 && daysUntilEnd >= 0
+    }
+}

app/src/main/java/io/github/wulkanowy/utils/SchooldaysValidator.kt

@@ -1,16 +0,0 @@
-package io.github.wulkanowy.utils
-
-import com.google.android.material.datepicker.CalendarConstraints
-import kotlinx.parcelize.Parcelize
-import java.time.temporal.ChronoUnit
-
-@Parcelize
-class SchoolDaysValidator(val start: Long, val end: Long) : CalendarConstraints.DateValidator {
-
-    override fun isValid(dateLong: Long): Boolean {
-        val date = dateLong.toLocalDateTime()
-
-        return date.until(end.toLocalDateTime(), ChronoUnit.DAYS) >= 0 &&
-            date.until(start.toLocalDateTime(), ChronoUnit.DAYS) <= 0
-    }
-}

app/src/main/java/io/github/wulkanowy/utils/TimeExtension.kt

@@ -8,7 +8,6 @@ import java.time.DayOfWeek.SUNDAY
 import java.time.Instant
 import java.time.LocalDate
 import java.time.LocalDateTime
-import java.time.LocalTime
 import java.time.Month
 import java.time.ZoneId
 import java.time.ZoneOffset
@@ -23,13 +22,13 @@ private const val DEFAULT_DATE_PATTERN = "dd.MM.yyyy"
 fun String.toLocalDate(format: String = DEFAULT_DATE_PATTERN): LocalDate =
     LocalDate.parse(this, DateTimeFormatter.ofPattern(format))
 
-fun LocalDateTime.toTimestamp() =
+fun LocalDateTime.toTimestamp(tz: ZoneId = ZoneId.systemDefault()) =
-    atZone(ZoneId.systemDefault()).withZoneSameInstant(ZoneOffset.UTC).toInstant().toEpochMilli()
+    atZone(tz).withZoneSameInstant(ZoneOffset.UTC).toInstant().toEpochMilli()
 
-fun Long.toLocalDateTime(): LocalDateTime =
+fun Long.toLocalDateTime(tz: ZoneId = ZoneId.systemDefault()): LocalDateTime =
-    LocalDateTime.ofInstant(Instant.ofEpochMilli(this), ZoneId.systemDefault())
+    LocalDateTime.ofInstant(Instant.ofEpochMilli(this), tz)
 
-fun LocalDate.toTimestamp() = atTime(LocalTime.now()).toTimestamp()
+fun LocalDate.toTimestamp(tz: ZoneId = ZoneId.systemDefault()) = atStartOfDay().toTimestamp(tz)
 
 fun LocalDate.toFormattedString(pattern: String = DEFAULT_DATE_PATTERN): String =
     format(DateTimeFormatter.ofPattern(pattern))

app/src/test/java/io/github/wulkanowy/utils/TimeExtensionTest.kt

@@ -7,6 +7,7 @@ import org.junit.Test
 import java.time.LocalDate.of
 import java.time.LocalDateTime
 import java.time.Month.JANUARY
+import java.time.ZoneOffset
 import java.util.Locale
 
 class TimeExtensionTest {
@@ -25,7 +26,10 @@ class TimeExtensionTest {
     @Test
     fun toFormattedStringLocalDateTimeTest() {
         assertEquals("01.10.2018", LocalDateTime.of(2018, 10, 1, 10, 0, 0).toFormattedString())
-        assertEquals("2018-10-01 10:00:00", LocalDateTime.of(2018, 10, 1, 10, 0, 0).toFormattedString("uuuu-MM-dd HH:mm:ss"))
+        assertEquals(
+            "2018-10-01 10:00:00",
+            LocalDateTime.of(2018, 10, 1, 10, 0, 0).toFormattedString("uuuu-MM-dd HH:mm:ss")
+        )
     }
 
     @Test
@@ -222,4 +226,18 @@ class TimeExtensionTest {
             assertEquals(of(2020, 10, 18), endExamsDay)
         }
     }
+
+    @Test
+    fun getLocalDateToTimestampUTC() {
+        assertEquals(0L, of(1970, 1, 1).toTimestamp(ZoneOffset.UTC))
+        assertEquals(946684800000L, of(2000, 1, 1).toTimestamp(ZoneOffset.UTC))
+        assertEquals(1640131200000L, of(2021, 12, 22).toTimestamp(ZoneOffset.UTC))
+    }
+
+    @Test
+    fun getLocalDateTimeToUtcTimestamp() {
+        assertEquals(0L, LocalDateTime.of(1970, 1, 1, 0, 0, 0).toTimestamp(ZoneOffset.UTC))
+        assertEquals(946684800000L, LocalDateTime.of(2000, 1, 1, 0, 0, 0).toTimestamp(ZoneOffset.UTC))
+        assertEquals(1640131200000L, LocalDateTime.of(2021, 12, 22, 0, 0, 0).toTimestamp(ZoneOffset.UTC))
+    }
 }