Cron Expression Parser turns a cron line into a readable sentence and lists the next times it will fire, in UTC. It understands the five standard fields, plus an optional leading seconds field, with ranges, lists, steps, and month and weekday names.
Parsing and the run search happen in your browser. Nothing is uploaded.
UTC. The search steps forward from the current moment on your device.
If both are restricted, a run matches when either is satisfied, which is how standard cron behaves.
Yes. A six-field expression is read as seconds, minutes, hours, day-of-month, month, day-of-week.
No. It all runs in the page.