Tide · Triggers and selection

Clock trigger and time zones

A clock trigger (on.clock) fires at a local time (at) in a time zone (tz). Each occurrence is identified by its date in that zone, whatever its UTC time. When DST ends, Vienna has 02:30 twice on Sunday 25 October: that date still has one run, at the first 02:30, and from then on 02:30 is one hour later in UTC.

Reflex

{
  id: 'books.close',
  intent: 'Close the day’s books at 02:30, every night.',
  on: {
    clock: { every: 'day', at: '02:30', tz: 'Europe/Vienna' },
  },
  effect: {
    name: 'books.close',
    input: { day: { $ref: '$.occurrence.key' } },
  },
}

Period covered, Vienna time

['2026-10-23 12:00', '2026-10-26 12:00']

Runs: date, local time, UTC

[
  { day: '2026-10-24', vienna: '02:30', utc: '00:30' },
  { day: '2026-10-25', vienna: '02:30', utc: '00:30' },
  { day: '2026-10-26', vienna: '02:30', utc: '01:30' },
]

Output matches the expected value

Runs in this page on the installed package. The input and the expected output are defined by the example.