YunoHost app settings system and Debian timezone changes: who propagates the new zone to app databases?

YunoHost does not provide a global hook or native mechanism that automatically propagates a Debian-level timezone change to all installed application databases. The behavior depends entirely on how each individual community-maintained package was authored to handle time.

In the YunoHost ecosystem, applications generally fall into two categories regarding time: those that read the system clock at runtime (via /etc/localtime or the TZ environment variable) update automatically, and those that store a fixed timezone value in their own internal database or configuration file during installation or the last manual update.

The Recommended Approach

To ensure an application reflects a new timezone without your changes being overwritten during an update, follow these steps:

1. Update the System Timezone: Use timedatectl set-timezone Region/City to update the underlying Debian OS.
2. Check App Settings: Run yunohost app setting list to see if the specific app exposes a timezone variable.
3. Update via YunoHost: If the variable exists, update it using yunohost app setting set timezone="Region/City". This ensures the YunoHost configuration system is aware of the change and the configure script can maintain the value during future upgrades.
nn
4. Restart the Service: Restart the app using yunohost restart to force the application to reload its configuration.

Verification Methods

Since there is no single "sync" status, you must verify each app individually. You can use the following methods:

• Admin UI: Check the application's internal dashboard or settings (e.g., log timestamps, event schedules).
• Logs: Inspect the app logs using tail -f /var/log//log to see if log entries match the new system offset.
• Database Query: For database-heavy apps (like Nextcloud or WordPress), query the internal tables to check if the timezone column has been updated.

Note: This analysis assumes you are using a current stable YunoHost release. If an app does not show a timezone setting via yunohost app setting, it likely relies on the system clock or requires a manual database update which may be volatile.