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systemd Timer & OnCalendar Builder

Builds and explains systemd OnCalendar expressions and timer units, converts from cron and lists the next runs.

systemd Timer & OnCalendar Builder

The schedule

Next runs

#When (UTC)
timer unit
Explanation

01

What it does

Builds and explains systemd OnCalendar expressions and timer units, converts from cron and lists the next runs.

  • OnCalendar grammar (weekday ranges, repetition /, ~ last day, shorthand like daily/weekly, time zones), next-elapse computation with DST …
  • Complements cron-expression-explainer

02

Private by design

Everything happens in your browser. Nothing you type, paste or upload is sent anywhere, and it keeps working offline once the page has loaded.

03

What you get

A .timer unit, an explanation and the next runs, with a Copy and a Download button on every result.

  • systemd
  • OnCalendar
  • cron

Why it matters

Builds and explains systemd OnCalendar expressions and timer units, converts from cron and lists the next runs.

OnCalendar grammar (weekday ranges, repetition /, ~ last day, shorthand like daily/weekly, time zones), next-elapse computation with DST via Intl, Persistent/RandomizedDelaySec/AccuracySec notes; cron-to-timer converter covering standard 5-field cron. Complements cron-expression-explainer. Everything runs in your browser; nothing you paste is sent unless you press Fetch.

How to use it

  1. Paste or type the input the tool asks for.
  2. Read the summary and the table or preview.
  3. Adjust the options if you need a different result.
  4. Copy or download the output. Nothing leaves this page.

FAQ

Is my input uploaded?

No. The work runs in your browser and nothing you type, paste or upload is sent anywhere.

Will this change my site for me?

No. It shows results and, where it writes rules or files, you copy them and apply them yourself.

Can I rely on this as official guidance?

It follows public documentation and well-known algorithms, and tells you where it is a subset or a simulation. Confirm critical changes in the official tool or a staging environment.

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