FAQ

Common questions about Cron Time Analyzer.

What is the 2-3 AM DST danger zone?

During Daylight Saving Time transitions, clocks jump forward from 2:00 AM to 3:00 AM (spring) or back from 2:00 AM to 1:00 AM (fall). Jobs scheduled in this window may run twice, be skipped entirely, or behave unpredictably depending on your system's timezone handling.

Which cron syntax does this tool support?

It supports the standard 5-field cron format: minute, hour, day of month, month, and day of week. This covers the vast majority of Linux crontab entries and common scheduler configurations.

Why should I avoid scheduling jobs at 2:00 or 3:00 AM?

Many system maintenance tasks, backups, and batch jobs default to early morning hours. However, the 2-3 AM window is exactly when DST changes occur in many timezones, which can cause jobs to run twice, skip a run, or overlap with other tasks. Scheduling outside this window reduces operational risk.

Is my cron expression sent to a server?

No. All analysis happens locally in your browser. Your cron expressions never leave your device, making it safe to test sensitive production schedules.