Set the language

locale: in the app block sets the language of the text the engine draws around your application: buttons, error pages, form messages, empty states, and the way numbers, money and dates are written.

app my_club "My Club" {
  locale:   en
  timezone: Europe/Berlin
}

Two values are accepted:

Value	Language
en	English. This is the default when an application declares no locale:
de	German

Any other value is a compile error. The message names the two values the engine can draw.

Your own labels, help texts and messages are not translated. They are shown as you wrote them.

What the locale changes

	en	de
a date	2026-07-01	01.07.2026
a time	2026-07-01 15:30	01.07.2026, 15:30
a whole number	1,234	1.234
an amount of money	€1,234.50	1.234,50 €
an amount in a form field	1234.50	1234,50
a CSV export	comma-separated, . before the cents	semicolon-separated, , before the cents

A date field accepts ISO dates (2026-07-01) and German dates (01.07.2026) in both locales. An amount field reads the locale’s own notation: under en, 1,234.50 is one thousand two hundred and thirty-four euros fifty and 12,50 is refused; under de it is the other way round. The engine refuses an ambiguous amount instead of guessing a factor of a hundred.

The locale: changes no stored value. Money is always stored in cents and a date always as an ISO date.

Pages that belong to no application

The login page, the application chooser and the administration pages under /matterdata belong to the organization, not to one application. They are drawn in English.