Recurrence Rule Calculator
Generate recurring dates from a start date with daily/weekly/monthly/yearly frequency and interval; monthly and yearly steps clamp to the last valid day of the target month.
Description
Generate a finite daily, weekly, monthly, or yearly sequence from an ISO start date.
Recurrence Rule Calculator generate a finite daily, weekly, monthly, or yearly sequence from an ISO start date.
Use this for simple previews and deterministic schedules where a fixed interval and occurrence count are enough.
When to use Recurrence Rule Calculator
Use this for simple previews and deterministic schedules where a fixed interval and occurrence count are enough.
How it works
The start date is the first occurrence. Daily and weekly steps add fixed UTC days; monthly and yearly steps clamp an invalid target day to that month's last day.1
Interpreting the result
Keep the input units, direction conventions, encoding, and ordering rules visible when reusing the result. Preserve the full returned value for downstream calculations and round only for presentation.
Assumptions and limitations
This is not a full RFC 5545 RRULE engine: it has no BYDAY, exclusions, time zones, end date, or skipped-invalid-date semantics. Clamping can change subsequent day-of-month values.