Date Time Picker

Prerequisite

The date time picker relies on parts of thejava.time API which are only available on Android API levels >= 26. Therefore, in order to make this library backwards comparability with older Android API a few options have to be set in your app/module build.gradle file which enables desugaring:

android {
    ...
    compileOptions {
      // Flag to enable support for the new language APIs
      coreLibraryDesugaringEnabled true

      // Sets Java compatibility to Java 8
      sourceCompatibility JavaVersion.VERSION_1_8
      targetCompatibility JavaVersion.VERSION_1_8
    }
    ...
}

dependencies {
  ...
  coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.9'
}

Note, this only has to be done if you intend to target an Android API level < 26. To find out more about desugaring you can check out: https://developer.android.com/studio/write/java8-support#library-desugaring.

Documentation

Date Picker

val dialogState = rememberMaterialDialogState()
MaterialDialog(
    dialogState = dialogState,
    buttons = {
        positiveButton("Ok")
        negativeButton("Cancel")
    }
) {
    ...
    datepicker { date ->
        // Do stuff with java.time.LocalDate object which is passed in
    }
}

/* This should be called in an onClick or an Effect */ 
dialogState.show()

Time Picker

val dialogState = rememberMaterialDialogState()
MaterialDialog(
    dialogState = dialogState,
    buttons = {
        positiveButton("Ok")
        negativeButton("Cancel")
    }
) {
    ...
    timepicker { time ->
        // Do stuff with java.time.LocalTime object which is passed in
    }
    ...
}

Theming

Both the date and time pickers have a colors argument which can be used to modify colors for the background and text of different elements within the dialog. For example to change the header background color of the date picker dialog you can use the following code:

datepicker(colors = DatePickerDefaults.colors(headerBackgroundColor = Color.Red)) 

To find out about other colors which can be changed have a look at the arguments of DatePickerDefaults.colors and TimePickerDefaults.colors.