How Claude turns "every weekday" into a call schedule

You never have to learn cron to use ReminderIt. You describe the rhythm in ordinary words and Claude converts it into the format the scheduler needs. Still, it helps to see what happens under the bonnet, so you can phrase requests in a way that lands cleanly the first time.

Two ways to describe a repeat

ReminderIt understands recurring reminders in two shapes. A cron expression pins calls to specific clock positions, like weekday mornings or the first of the month. An interval_days value spaces calls evenly, like every 3 days regardless of which weekday that lands on.

Claude chooses between them based on how you speak. "Every weekday" or "on Mondays and Thursdays" points to cron. "Every other day" or "once a fortnight" points to interval_days.

Reading a cron expression

A cron expression has five fields: minute, hour, day-of-month, month, and day-of-week. So 0 8 * * 1-5 reads as minute 0, hour 8, any day-of-month, any month, weekdays one to five. In plain English: 8am, Monday to Friday.

You do not write these yourself, but recognising the pattern makes it easy to sanity-check what Claude confirms back to you.

Real examples, side by side

"Every weekday at 8am" becomes 0 8 * * 1-5. "Every day at 9pm" becomes 0 21 * * *. "Mondays at 9am" becomes 0 9 * * 1. "The 1st of every month at 10am" becomes 0 10 1 * *. "Weekends at 10:30am" becomes 30 10 * * 6,0.

For spacings rather than fixed days: "every 3 days" is interval_days of 3, and "every week" can be interval_days of 7. Both keep an even gap from the last call rather than tying to a weekday.

An example conversation

Ask: "Set a call every weekday at 8am, Europe/London, to say the morning stand-up starts in ten minutes." Claude calls create_reminder with cron 0 8 * * 1-5, the zone Europe/London, and your message text, then reads the schedule back to you.

If you then say "actually make it 8:15," Claude uses update_reminder to change the minute field to 15, giving 15 8 * * 1-5. Same reminder, new rhythm, no rebuild.

Phrasing that avoids surprises

Ambiguous words are where mistakes creep in. "Every morning" is clear enough, but "twice a day" needs two times, so name them: "9am and 9pm." Claude will create two reminders rather than guessing.

And because every schedule is anchored to a zone, include it: "weekdays at 8am, America/New_York." A quick follow-up of "show me the next few" runs list_upcoming so you can confirm the translation matches what you pictured.