Maintenance windows
A maintenance window (a silence in the API) stops notifications for a monitor, or for everything, during a period. Evaluation continues underneath: when the window ends, an alert that is still active is notified once, rather than appearing out of nowhere after two hours.
- Alerts → Maintenance: the list of windows, with Active now or Scheduled, and the form to add one.
- Monitor page → Silence 1 h / Silence until…: a quick one-off window for the whole monitor.
- ++ctrl+k++ → Schedule maintenance.
Snooze, on one alert in the Now tab or a monitor page, is a
smaller version of the same mechanism: a one-off window scoped to that one
alert’s exact labels rather than the whole monitor, so a sibling rule keeps
talking. It shows up here too, named Snooze · …. See
Getting rid of an alert.
One-off window
Section titled “One-off window”| Field | Meaning |
|---|---|
| Name | Shown in the list and in history. |
| Monitor | Leave empty to cover every monitor. |
| Start, End | Absolute times. The window includes the start and excludes the end. |
| Comment | Optional. Why the window exists. |
One-off windows are purged once they are over.
Weekly window
Section titled “Weekly window”| Field | Meaning |
|---|---|
| Days | Which days of the week (Monday to Sunday). |
| From, To | Local time in the window’s time zone. If To is at or before From, the window spills over midnight (“23:00 → 01:00” belongs to the day it starts on). |
| Time zone | An IANA name such as Europe/Paris. Pre-filled with your browser’s zone. |
Monthly window
Section titled “Monthly window”| Field | Meaning |
|---|---|
| On a weekday | First, Second, …, Fifth or Last, plus the day — “the first Sunday”, “the last Friday”. |
| On a date | One or more days of the month, from 1 to 31, separated by commas (“1, 15”). |
| From | Local start time, in the window’s time zone. |
| For | How long the window lasts, as real elapsed time. A monthly window may run longer than a day. |
| Time zone | As above. |
A month that does not contain the occurrence is skipped rather than approximated: there is no 31st in February, and no fifth Sunday in April 2026, so the window simply does not open that month. The list shows the next occurrence the server computed, so you can check it at a glance.
DumbMonit has no cron expressions, on purpose: a cron expression names instants, and a maintenance window needs a duration. Days of the month and “the n-th weekday” cover the calendars people actually keep, and read back in one line.
Time zones and daylight saving
Section titled “Time zones and daylight saving”A recurring window opens at its local wall-clock time and then runs for its duration in real time. Both halves matter:
- The local hour does not drift. “Every Sunday at 02:00 in
Europe/Paris” is 01:00 UTC in winter and 00:00 UTC in summer — the window follows the clock change instead of sliding by an hour twice a year. - The duration does not stretch. On the night the clock goes back, 02:00 to 04:00 on the wall would last three real hours; the window still lasts two. On the night the clock jumps forward and 02:00 does not exist, the window opens as soon as the clock resumes.
A window saved before time zones existed keeps its fixed UTC offset and behaves exactly as it did. Re-save it with a zone to make it follow the clock changes. A zone name the server does not know is refused when you save, with an example.
Matchers
Section titled “Matchers”A window can also be limited by exact label matches (matchers in the API):
all of them must match the alert’s labels, for example tag_role = lab and
__name__ = dumbmonit_up. A window with no monitor and no matcher silences the
whole instance. Overlapping windows are fine; the first one that covers the
moment explains the silence.
What a silenced alert looks like
Section titled “What a silenced alert looks like”The alert keeps its phase and shows silenced: true; the history records the
transition with notified: false and the reason. Disabling a window
(enabled: false) keeps it in the list without effect.
Recoveries during a window
Section titled “Recoveries during a window”A window silences announcements of problems. By default it silences the
recovery message too: an alert that was announced and then resolves while a
window covers it sends nothing, and nothing is sent late once the window ends.
The alert’s history still records the resolution (notified: false, reason
maintenance window), so the timeline stays accurate; only the notification is
skipped.
To be told about recoveries even during maintenance, turn on Also send
recoveries during a silence or maintenance window in Settings → Notifications
& reports → Notification policy, or set resolutions_during_silence to send
with PUT /api/notify/policy (suppress is the default). The setting is
global and applies to every silence and window.
On a public status page
Section titled “On a public status page”A monitor covered by a maintenance window is shown as Maintenance on any status page that lists it, instead of red. If nothing else on the page is down or degraded, the page’s overall state reads Maintenance as well. Only windows that name a monitor — or whose matchers are monitor-level labels — surface this way; a window limited to one metric stays an alerting matter.