How does Every N weeks use the start date?

The start date is the first occurrence. Each following result is the selected number of complete weeks after the previous result.

What happens to the 31st in a shorter month?

That month is skipped because it has no matching 31st. The pattern resumes in the next month that contains that day.

Can I find the last Friday of each month?

Yes. Choose First or last weekday each month, select Friday and then choose Last.

Are leap years supported?

Yes. Gregorian leap-year rules are used, so a monthly pattern for day 29 includes February 29 in leap years.

How many recurring dates can I generate?

Occurrence mode supports from 1 through 1,000 results. End-date mode lists every match inside the selected inclusive range.

Date & Time Calculators

Date Pattern Calculator

Find dates matching weekly and monthly recurring calendar patterns.

Free foreverRuns in your browserNo sign-up

Start datePattern

Weekday

Stop after

Occurrences

About the Date Pattern Calculator

The Date Pattern Calculator finds calendar dates that match a recurring weekly or monthly rule. Results can stop at an end date or after a chosen number of occurrences.

Weekly rules include every selected weekday and an interval anchored to the start date, such as every two weeks. Monthly rules include the first or last selected weekday and a specific numbered day.

Month boundaries are handled deliberately. A rule for the 31st skips months without a 31st instead of moving the occurrence to another date, while February 29 appears when the range includes a leap year.

Candidate dates are generated directly from the pattern rather than scanning every calendar day. The calculation runs locally in the browser and supports up to 1,000 displayed occurrences.

Key features

Every selected weekday pattern
Configurable every N weeks pattern
First or last weekday of each month
Specific numbered day of each month
End-date or occurrence-count limits
Leap-year and month-boundary handling

How to use

1Choose the first eligible date and a recurring pattern.
2Configure the weekday, week interval, monthly position or day number shown for that pattern.
3Choose whether to stop at an end date or after a number of occurrences.
4Review the matching ISO dates and their readable calendar labels.

Frequently asked questions

How does Every N weeks use the start date?: The start date is the first occurrence. Each following result is the selected number of complete weeks after the previous result.
What happens to the 31st in a shorter month?: That month is skipped because it has no matching 31st. The pattern resumes in the next month that contains that day.
Can I find the last Friday of each month?: Yes. Choose First or last weekday each month, select Friday and then choose Last.
Are leap years supported?: Yes. Gregorian leap-year rules are used, so a monthly pattern for day 29 includes February 29 in leap years.
How many recurring dates can I generate?: Occurrence mode supports from 1 through 1,000 results. End-date mode lists every match inside the selected inclusive range.