Cron Expression Reader

A cron expression reader is a tool that converts a crontab schedule into plain English so you can confirm when a scheduled job will actually run. A standard cron expression has five space-separated fields: minute (0 to 59), hour (0 to 23), day of month (1 to 31), month (1 to 12), and day of week (0 to 7, where both 0 and 7 mean Sunday). Each field accepts a wildcard (*) for 'every', a range like 1-5, a list like 1,3,5, and a step like */15 for 'every fifteenth'. Combining these is what makes expressions like '15 3 1-7 * 1' so hard to parse at a glance. Xevon Tools' Cron Expression Reader translates the whole expression and breaks out each field individually, so you can see precisely which part triggers a run. It also recognizes the shorthand macros, expanding @daily to '0 0 * * *', @hourly to '0 * * * *', and so on. The most important gotcha it helps you catch is the day-of-month versus day-of-week interaction. In standard Vixie cron, if you restrict both of those fields (neither is a wildcard), the job runs when either condition is satisfied, not when both are. So '0 0 1 * 1' does not mean 'midnight on the 1st only if it is a Monday'; it means 'midnight on the 1st of every month, and also midnight every Monday', which is a frequent source of jobs firing more often than intended. Reading the expression in English makes that behavior obvious before it bites you in production. Typical uses include auditing an inherited crontab, validating a new schedule before it ships in a CI/CD pipeline, documenting a job's timing for non-technical colleagues, and debugging a job that fires at the wrong moment. Because parsing happens in your browser, an internal schedule from a production server stays private.