bevy-timers

name	bevy-timers
description	Reference for Bevy timers — Timer as resource, component, or Local; tick, finished/just_finished, TimerMode::Once vs Repeat.
metadata	{"crate":"bevy_time","bevy":"0.19"}

Timer modes

• TimerMode::Once — ticks to 0 once, resets manually
• TimerMode::Repeat — auto-resets when finished

Timers tick up from zero to their Duration.

Timer as resource

#[derive(Resource)]
struct MatchTime(Timer);

impl Default for MatchTime {
  fn default() -> Self { Self(Timer::from_seconds(60.0, TimerMode::Once)) }
}

fn countdown(time: Res<Time>, mut match_time: ResMut<MatchTime>) {
  match_time.0.tick(time.delta());
}

fn end_match(match_time: Res<MatchTime>) {
  if match_time.0.finished() { /* game over */ }
}

Timer as component

#[derive(Component)]
struct Cooldown(Timer);

fn tick_cooldowns(mut commands: Commands, mut cooldowns: Query<(Entity, &mut Cooldown)>, time: Res<Time>) {
  for (entity, mut cd) in &mut cooldowns {
    cd.0.tick(time.delta());
    if cd.0.finished() {
      commands.entity(entity).remove::<Cooldown>();
    }
  }
}

Local timer

fn local_timer(time: Res<Time>, mut timer: Local<Timer>) {
  timer.tick(time.delta());
  if timer.just_finished() {
    info!("Timer finished");
  }
}

Key methods

Method	Description
tick(delta)	Advance the timer
finished()	True if timer has reached duration
just_finished()	True if finished on the last tick
fraction()	Progress as f32 (0.0 to 1.0)
reset()	Reset to zero
duration() / set_duration()	Get/set duration

Time resource

fn time_info(time: Res<Time>) {
  info!("delta: {:?}", time.delta());
  info!("elapsed: {:?}", time.elapsed());
}