Recurrence & Events

A rule like "every 30 days" and a rule like "the second Tuesday of every month" both produce a repeating sequence of dates, but they behave very differently over time. This category covers generating and reasoning about recurring dates, including next-occurrence lookups, every-N-days schedules, weekly and monthly rules, nth-weekday rules, and what happens when a recurrence rule lands on a date that does not exist in every month, like the 31st.

Fixed-interval recurrence drifts against the calendar

A rule anchored to a fixed number of days (every 14 days, every 30 days) walks steadily across the calendar. It will not land on the same weekday indefinitely, and "every month" is not the same as "every 30 days" over a long enough run, since months vary in length. A rule anchored to a calendar position (the last Friday of the month, the 15th) does not drift that way, but it does have to define what happens when the 15th falls on a weekend, or when "the 31st" lands in a month that stops at 30 or 28 days. Naming which kind of rule is in play, and what its edge-case behavior is, is the actual content of this category.

An exception is not a broken schedule

A recurring meeting that gets moved once, or a recurring payment that skips a holiday, is still one schedule with one documented exception, not a reason to abandon the rule. This category treats exception handling (skip, shift, or substitute) as part of the recurrence model itself rather than something a user has to work around by hand.

Where to go next

For a single non-repeating deadline or countdown, see Deadlines & Project Capacity. For a recurring event that needs to be shown in more than one time zone, see Time Zones & Meetings.

Recurrence & Events tools

• Recurring Date GeneratorGenerate a bounded preview of occurrences for a daily, weekly, monthly, or annual rule.
• Recurrence Drift ComparatorCompare a calendar rule against a fixed-interval rule and see how far apart they drift.
• Next Occurrence CalculatorFind the next valid occurrence of a recurrence rule strictly after a reference date.
• Every-N-Days Schedule GeneratorGenerate a fixed-day cadence (every N days) from a start date, with no calendar drift.
• Weekly / Biweekly Schedule GeneratorGenerate a schedule from a set of weekdays repeating every 1 or more weeks.
• Monthly Date Rule GeneratorGenerate a day-of-month recurrence with an explicit policy for months lacking that day.
• Nth-Weekday Recurrence GeneratorGenerate an ordinal-weekday recurrence, like the third Monday of every month.
• End-of-Month Recurrence PlannerGenerate a schedule that always lands on the true last day of the month.
• Event Countdown / Count-Up PlannerCount down to a future event, or count up from a past one, in whole calendar days.
• Streak / Interval TrackerFind the longest consecutive-day streak and every gap in a list of dates you enter.
• Anniversary PlannerPlan a repeating annual anniversary, with a policy for a Feb 29 original date.
• Reminder Cadence PlannerGenerate a recurring schedule, then offset it by a lead time to get reminder dates.
• Schedule Exception ResolverApply inclusion and exclusion dates to a recurrence rule and see the resolved schedule.
• Recurring Business-Day Event GeneratorGenerate first, last, or nth business-day events across consecutive months.
• Recurrence Collision FinderFind dates that coincide across two or more independent recurrence rules.
• Recurring Schedule End-Date CalculatorSolve the final occurrence date of a recurrence rule from a start and count.
• Multi-Cadence Calendar PlannerDisplay several independent recurring schedules together on one timeline.