Cron Lab

I never remember whether the day-of-week field starts at zero, so I built the tool I keep googling for. Paste an expression and it tells you what it means, how often it fires on average, and the next eight run times. Go the other way and the configurator covers the everyday schedules — every N minutes, daily, weekly, monthly — with an advanced panel that gives you per-field control over wildcards, steps, ranges, and explicit value lists.