Customizable Date/Time Format

[NOBODY12021]

It would be very nice to be able to configure the date/time format in upptimerc.yml, for example the ability to switch to day/month/year instead of month/day/year, or use a 24h clock instead of am and pm.

[M1XZG]

@NOBODY12021, this is already possible for locale-based date and time formats, although it isn’t very obvious from the current documentation.

Add a top-level i18n section to .upptimerc.yml:

i18n:
  locale: en-GB

en-GB uses day/month/year dates and normally uses a 24-hour clock, so it should give you the two changes in your example. The setting belongs at the top level alongside sites and status-website, rather than inside status-website.

If you already have translated labels configured, add locale to the existing block:

i18n:
  locale: en-GB
  allSystemsOperational: All systems are operational
  incidentReport: "Incident #$NUMBER report"

Upptime’s status page passes this value into JavaScript’s toLocaleString() and toLocaleDateString() functions when it displays incident, maintenance and history dates. The default is currently en-US, while the incident display code uses the configured locale.

A few useful examples are:

i18n:
  locale: en-GB  # 28/08/2026, normally with a 24-hour clock

i18n:
  locale: de-DE  # 28.08.2026, normally with a 24-hour clock

i18n:
  locale: en-US-u-hc-h23  # US date order, but force a 24-hour clock

This controls formatting through locale conventions rather than accepting an arbitrary pattern. A completely custom format such as YYYY-MM-DD HH:mm would still require a status-page change, but day/month/year plus a 24-hour clock should only require locale: en-GB.