Cron Analyzer - analyze cron schedules and overlaps

Paste the cron above. CronTool validates its fields, writes an English sentence, lists five next runs in the selected timezone, and plots the visible month. Use the multi-cron visualizer to analyze several schedules together.

It outputs editable fields with help, a plain-English sentence, lint messages, five next runs, a navigable month calendar, and Copy-as formats. It does not identify which scheduler dialect originally produced the expression.

Yes. It validates each token against its field, including minutes 0-59, hours 0-23, and day-of-month 1-31, then highlights the field that fails.

Yes, on the multi-cron page. It overlays the visible month's runs and automatically lists up to five source pairs that fire in the same minute, including a sample time and monthly count.

Yes. Put the schedules in the multi-cron view to expose top-of-hour bunching and overlapping pairs. Stagger fixed minutes, or use Jenkins H when Jenkins should choose a stable hashed minute. Expression: 0 * * * *

It shows an informational warning from 288 runs per day and a warning at 1,440 or more. The latter is every minute or several times a minute, depending on Extended mode. Expression: * * * * *

Yes. In Standard mode it warns that Unix cron ORs day-of-month and day-of-week, so 0 9 1 * 1 runs on every Monday and every first of the month. Expression: 0 9 1 * 1

It means the step restarts at its field boundary. */2 in day-of-month restarts at day 1 each month, while a month step restarts at January; neither is a continuous elapsed-time interval. Expression: 0 0 */2 * *

CronTool separately checks fixed day/month combinations. 0 0 30 2 * parses, but its status says the expression never fires because February 30 does not exist. Expression: 0 0 30 2 *

For a fixed 01:00-03:00 hour, it warns when the selected timezone has a DST transition within 60 days. The message says whether the hour may be skipped or repeated. Expression: 30 2 * * *

Treat the selected IANA timezone as the clock used for next runs and calendar labels. Your production scheduler may use its host zone, UTC, or its own timezone setting.

Six pasted fields are ambiguous in Standard mode, so the lint offers to switch to Extended before issuing other advice. Extended mode handles seconds-first or year-bearing dialects.

No. CronTool parses supported forms but has no dialect selector or compatibility verdict. Consult the dialect matrix, then use Copy as to produce a target format and read any conversion caveat.

Preserve cron=<expression> and add mode=extended when needed. Add tz=<IANA zone> yourself if the recipient must see the same timezone; the Copy link action does not include it.

Static analysis cannot prove that a command ran. CronTool cannot see your server's PATH, environment, permissions, logs, or process state, and it never executes commands.