DatePicker

A self-contained calendar month grid for picking a single day. The displayed month is managed internally (seeded from defaultMonth, then value, then today) and navigated with the header chevrons. Date math is pure Kotlin — no date library and no system clock is read.

Import

import io.github.heartcoolman.prism.ui.PrismDatePicker
import io.github.heartcoolman.prism.ui.PrismDate

Basic usage

var date by remember { mutableStateOf<PrismDate?>(null) }

PrismDatePicker(
    value = date,
    onChange = { date = it },
)

Highlighting today

Pass today to outline the current day. Because no clock is read, you supply it explicitly. month is 1-12.

var date by remember { mutableStateOf<PrismDate?>(PrismDate(2026, 6, 30)) }

PrismDatePicker(
    value = date,
    onChange = { date = it },
    today = PrismDate(2026, 6, 30),
)

Seeding the displayed month

With no value, use defaultMonth to choose which month opens first (any day within it).

PrismDatePicker(
    value = null,
    onChange = { /* … */ },
    defaultMonth = PrismDate(2026, 1, 1),
)

API

PrismDatePicker

Parameter	Type	Default	Description
modifier	Modifier	Modifier	Modifier applied to the surface.
value	PrismDate?	null	Selected date, or null when nothing is selected.
onChange	(PrismDate) -> Unit	{}	Fired with the clicked day.
defaultMonth	PrismDate?	null	Month shown on first render; falls back to value, then today.
today	PrismDate?	null	Day to outline as "today"; nothing is highlighted if null.

PrismDate

Field	Type	Description
year	Int	Full year.
month	Int	Month, 1-12.
day	Int	Day of month.

Assumes an enclosing PrismTheme { }. The selected day fills with PrismTheme.colors.accent; the today outline uses the same accent.