Recurring dates generates a list of future (or past) dates separated by a fixed interval — every N days, weeks, or months from a start date. Use it for medication refills, subscription renewals, standup series, garden watering, inspection cycles, and any schedule that repeats on calendar rhythm rather than ISO week labels.

Interval types

Every N days advances by exact day count — useful for 90-day prescription refills or 14-day quarantine checks. Every N weeks jumps by seven-day multiples from the anchor weekday. Every N months adds calendar months, preserving day-of-month when possible and clamping to month end when the target day does not exist (January 31 plus one month becomes February 28 or 29).

Month-based recurrence differs from every-thirty-days recurrence — three months from November 30 is February 28/29, not January 30. Choose the interval type that matches your policy language.

How to use the calculator

Enter start date, interval size, interval unit, and how many occurrences to list. Read the generated dates and copy into calendar apps or spreadsheets. Adjust count when you need a full year of reminders rather than a short preview list.

For payroll-like every-two-weeks schedules, also compare payday calculator output — biweekly pay is not always the same as every fourteen days from an arbitrary anchor if HR uses semimonthly rules.

Month-end and leap edge cases

Monthly recurrence on the 31st skips months with fewer days unless the tool clamps to last day — verify behavior against your use case. February anchors need leap-year awareness when scheduling annual reviews on the 29th.

Use days in month and last day of month to sanity-check month-end series before importing hundreds of rows into a CMMS.

Worked examples

A facilities team schedules fire extinguisher inspections every six months from last service date — they enter the service date, interval six months, and export twelve occurrences for the compliance binder.

A product team runs biweekly retrospectives every two weeks from sprint zero Monday — interval two weeks from that Monday produces consistent weekday anchors unlike every-fourteen-days from a midweek start that drifts weekdays over time... actually every 2 weeks from Monday stays Monday. Good.

A gardener waters every three days from first frost prep date through growing season — day-based interval ignores weekday names entirely.

Versus cron and weekday tools

Cron expressions handle wall-clock jobs on servers — see cron calculator for minute-hour-day-of-month syntax. Recurring dates here is human calendar output for planning, not machine scheduling.

Weekday counter counts how many Mondays fall in a range; recurring dates lists each Monday occurrence when interval is one week from a Monday start.

Import and documentation

Paste results into ICS or Google Calendar as individual events, or use the list as acceptance criteria for automated reminder services. Store start date and interval in policy docs so the next owner reproduces the series.

When migrating from every-30-days to every-1-month semantics, regenerate the full series — small drift accumulates across years if you only change the label without recalculating.

Healthcare and compliance

Clinical trial visit windows often specify day N, day N+28, day N+56 — day-based recurrence matches protocol language. Regulatory submissions should cite the generator inputs in appendices for audit trails.

Warranty expiration reminders every twelve months from purchase date should use month interval from purchase, not approximate 365-day day interval, when the contract says calendar months.

Common mistakes

Using day intervals when the contract says monthly produces drift relative to month-end billing. Starting from the wrong timezone midnight shifts dates for global teams — civil dates here assume the date you enter without UTC conversion.

Listing too few occurrences for annual events — request enough rows to cover the full planning horizon on the 2026 yearly calendar.

Software release trains

Teams shipping every two weeks from a fixed anchor Monday align release retrospectives with recurring date output — document the anchor in the engineering handbook so new release managers do not restart the cadence from arbitrary midweek dates.

Security patch windows every ninety days from last critical patch should use day-based interval, not calendar quarter boundaries, unless policy explicitly says quarterly.

Personal habits and reminders

Hydration or medication reminders every N days drift relative to weekdays — users who prefer same weekday should switch to week-based interval from a matching start date.

Export the first twelve occurrences to phone reminders, then regenerate when the anchor date changes after missed doses or skipped maintenance.

HOA and municipal inspections

Homeowners associations scheduling pool inspections every fourteen days from season opening should export the list to vendors with explicit start date — vendors assuming calendar month boundaries miss early-season weeks.

Municipal meter reading on ninety-day cycles uses day interval, not quarterly calendar labels — confirm interval type before copying city templates.

Library and archive due dates

Libraries extending due dates every three weeks from checkout day generate renewal lists with week-based recurrence — day-based every twenty-one days drifts weekday unless checkout always occurs same weekday.

Digital archive integrity checks every ninety days from ingest date should store anchor in catalog metadata for reproducibility.

Warranty reminders

Appliance warranties expiring twelve months from purchase should use month interval from purchase date, not day 365, when terms say twelve calendar months — regenerate the series when purchase date corrections arrive from POS data.

Fleet maintenance every six months from registration date should use month interval anchored to registration day — police fleets audit odometer service against this schedule in compliance reviews.

PTA newsletters listing every-other-week volunteer shifts should regenerate dates when school breaks remove a week — do not assume the old series still lands on correct weekdays after vacation.

Subscription renewals every 28 days drift across weekdays; monthly anchors on the same calendar day behave differently—label which pattern your 2026 forecast uses.

Related tools

See payday calculator, days from today, and the date tools hub.