Dates that follow a pattern
Real schedules rarely say "the 19th". They say "the third Monday of the month" (US federal holidays, board meetings, patch Tuesdays), "the last Friday" (payroll, reports), or "every two weeks from today" (paydays, medication, watering rotations). This calculator resolves both kinds of pattern: pick an occurrence and a weekday inside any month, or generate a repeating sequence at any day interval from a start date, with the next eight occurrences listed.
How the nth-weekday pattern works
Find the weekday of the 1st of the month, step forward to the first matching weekday, then add weeks. Every month has four or five of each weekday: five happens when the month's length and starting day leave room — a 31-day month starting on your weekday gives that weekday five occurrences. That is also why "the 5th Monday" sometimes does not exist, and this calculator says so plainly instead of rolling into the next month (a classic silent bug in pattern tools).
Famous pattern dates
Thanksgiving in the US is the fourth Thursday of November; Memorial Day is the last Monday of May; most US federal holidays are defined exactly this way (the Business Days Calculator uses these patterns for its holiday list). Biweekly schedules use the repeating mode with 14 days — note it stays glued to one weekday forever, while every-10-days schedules drift, which is why rotating rosters feel irregular. For working-day versions of a sequence, combine the dates here with the Business Date Calculator.
Worked example
The third Monday of October 2026 is October 19, 2026. That month's Mondays fall on the 5th, 12th, 19th and 26th — four in total — while Thursdays and Fridays each occur five times.
How to use this calculator
- Choose the pattern: nth weekday of a month, or every N days.
- For nth-weekday: pick the occurrence, the weekday and the month.
- For repeating: pick a start date and the interval in days.
- Read the answer in the green panel and the full list of occurrences in the table below.
“Every other week” vs “twice a month”
They are not the same: every two weeks is 26 occurrences a year, twice a month is 24 — the famous two "extra" paychecks for biweekly-paid workers. Pattern arithmetic like this is where the difference hides; use the repeating mode with 14 days to see a full year of biweekly dates, or count occurrences between two dates with the Date Difference Calculator.