Quiet hours – personal
Under Settings → Alerts you can set hours and days when your personal channels (e-mail, SMS) stay silent. Shared channels such as Slack are unaffected and everything still shows in the app. Tick But wake me for outages anyway to let confirmed outages through while warnings wait until morning.
Maintenance windows – per site or all sites (Pro)
Planned work should not alert anyone. Add a window with a start, a duration and optionally a daily/weekly repeat in your timezone. Checks keep running so your uptime history stays complete; alerts are recorded as suppressed – maintenance in the history and incidents during the window are marked as maintenance.