Display Schedule

A device can switch its screen off outside opening hours and back on in the morning, on a daily schedule with per-weekday selection. The schedule is off by default, so a device that has always stayed lit keeps doing so after an upgrade.

Configure it under Settings → Display schedule.

What actually happens at the scheduled time

Two things are sent on every transition, not one, because a device can have a TV on one HDMI port and a plain monitor on another:

Most desktop monitors do not answer CEC at all, so on those the screen goes black rather than powering down. Nothing needs configuring for this: the schedule is not hidden or disabled on a device with no CEC adapter.

Field reference

Times are wall-clock in the device’s configured timezone (Settings → Timezone), so they follow DST rather than drifting with it.

Note

The weekday numbering here is Monday=0 … Sunday=6, which is not the Monday=1 … Sunday=7 numbering used by asset scheduling ’s play_days. The two features were added at different times against different conventions; the web UI hides the difference behind the same day chips in both places.

Days and overnight schedules

display_power_days selects the days an on-period starts. For a schedule that runs past midnight, the small hours belong to the previous day’s on-period, so they are governed by the previous day’s checkbox.

For example, on 18:00 → 06:00 with only Friday selected:

A same-day schedule (on 08:00 → off 18:00) needs no special handling: the whole on-period falls on the selected day.

If the on and off times are identical, the schedule describes neither an on-period nor an off-period, and the device is left alone.

Deselecting every day means every day, not no day: an enabled schedule with no days selected would be silently inert, so the empty selection is treated as the full week. To stop the schedule entirely, switch it off.

Turning the schedule off

Disabling the schedule while the display is switched off restores it on the next tick, rather than leaving a black screen with no way back. This matters on a device with no CEC adapter, where the manual display-power buttons are hidden entirely.

Setting it through the API

The four fields are readable and writable on the v2 device-settings endpoint, alongside the rest of the settings page:

$ curl http://<device-ip>/api/v2/device_settings

$ curl -X PATCH http://<device-ip>/api/v2/device_settings \
    -H 'Content-Type: application/json' \
    -d '{
          "display_power_schedule_enabled": true,
          "display_power_on_time": "07:30",
          "display_power_off_time": "22:00",
          "display_power_days": "0,1,2,3,4"
        }'

Unlike the web form, which keeps the previous value and shows a warning, the API returns 400 for a malformed time or weekday: a client that explicitly sent a field should be told the value was wrong rather than have it reinterpreted. HH:MM:SS is accepted and normalized to HH:MM, and an empty display_power_days normalizes to every day.

See the API page for the full endpoint reference.

Manual control

Settings → Display power (marked Experimental) has “Turn display on” / “Turn display off” buttons for a one-off change. That section is CEC-only and appears only on devices that expose a CEC adapter, so it is not a substitute for the schedule on a plain monitor.

A manual change is temporary while the schedule is enabled. The schedule re-asserts the state it thinks the display should be in roughly every 10 minutes, so switching the screen on during an off-period buys about 10 minutes before it goes off again. That re-assertion is what makes the feature survive a viewer restart: without it, a viewer that restarted at 22:00 would come back lit and stay lit until morning.

Notes and limitations

• Transitions are applied within about 60 seconds of the configured time.
• Whether HDMI-CEC works at all depends on the display, the cable and the port. Many desktop monitors advertise no CEC in their EDID, and most x86 PCs have no CEC adapter. In that case the screen still goes black on schedule via local blanking; it just is not powered down.
• CEC is driven by the anthias-viewer container, which is the only one that can reach /dev/cec* on every board and every deployment. If the viewer is not running, display power reports an error.
• The System Info page has a “Display Power (CEC)” card showing what the device last read back over CEC:

  Reading	Meaning
  True / False	Every display that answered is on / in standby
  Mixed	Two displays are attached and disagree, or one is mid-transition
  No CEC display detected	Nothing answered. The normal reading for a plain monitor, and not a fault
  No CEC adapter	The board exposes no CEC hardware at all
  Not available	Same, short-circuited before the query was sent
  CEC error	The query could not be completed. The only reading that means something is wrong

Related documentation

• Asset scheduling : restrict individual assets to days and time windows.
• API reference : set the schedule programmatically with the v2 API.
• All documentation : the full Anthias documentation index.