Cronie scheduling
Cronie schedules: day fields, DST, and step values
Cronie is an implementation of the cron scheduling service: it runs in the background on systems such as Linux and starts commands at scheduled times. A cron expression specifies when to run; Cronie does the running. Our browser tool only explains the expression and previews matching times. You do not need to install Cronie to use it.
Use the five Cronie fields
Cronie reads minute, hour, day of month, month, and day of week. Use * , - and / only after confirming the deployment target is Cronie; Quartz and other schedulers use different field counts and operators.
Understand the day-field rule
When neither day field starts with *, Cronie uses OR. For example, 30 4 1,15 * 5 matches the 1st and 15th, plus Fridays. If either day field starts with *, both must match: 0 9 */2 * MON matches Mondays on odd-numbered dates, not every Monday. The position of * matters even in lists.
Steps reset within each field
*/23 in the minute field matches minutes 0, 23, and 46 each hour, not a continuous 23-minute interval. Use */n or a-b/n with a positive integer step. This tool accepts ascending ranges; use FRI-7 instead of a wrapping weekday range.
Preview time is not job proof
The tool scans the next 400 days in your browser timezone and lists up to five calendar matches, with UTC equivalents. It does not simulate a daemon. At a DST gap, a calendar time is absent; during a repeated hour, two different instants can match. Cronie can instead catch up or suppress duplicate fixed-time jobs during small clock changes. Check cron(8), CRON_TZ, host settings, and actual job logs; never use this preview as execution proof.
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