Calendar Weekday & Date Rule Finder
Find Friday the 13th, nth or last weekdays, and fixed days of month within a date range, then export a result list or all-day calendar events.
Ready. Explore the example or use the input controls to begin.
Scope and practical limits
Gregorian dates 0001–9999; ascending ranges up to 36,600 days and at most 5,000 results. Endpoints inclusive. Missing fifth weekdays or nonexistent days are skipped. Calendar rules do not determine official holiday observance or closures.
The tool processes your work in the browser. The website’s advertising and analytics follow its privacy and consent settings. Projects are not saved automatically. Media workspaces export their files directly rather than storing them in project JSON.
Using Calendar Weekday & Date Rule Finder
Find Friday the 13th, nth or last weekdays, and fixed days of month within a date range, then export a result list or all-day calendar events.
- Start with the example and set the relevant dates, range or clock settings.
- Review validation messages and the calculated results, including calendar conventions and day offsets.
- Download JSON or CSV; where available, export all-day calendar events. Save a project to retain your inputs.
Example
Find Friday the 13th in 2026: February 13, March 13 and November 13. Choose fourth Thursday to find 2026-11-26 among the monthly matches.
Questions & answers
Can it find the last weekday in each month?
Yes. Choose last weekday and select the weekday number. It returns the final matching weekday in each month of the range.
Does choosing fourth Thursday identify an official holiday?
It identifies a calendar pattern. Official holiday and observed-day rules depend on the jurisdiction and are not inferred.
Related tools
A useful next step for your task.
Everyday CalculatorsGregorian & Julian Calendar ConverterConvert batches of Gregorian and Julian calendar dates with leap-rule validation, weekday checks and a shared integer-day index.
Everyday CalculatorsEaster Date Finder & Calendar ExportFind Gregorian and traditional Julian-method Easter dates across a year range, compare their civil dates and export results or Gregorian Easter…
Everyday CalculatorsFind Clock Times from Hand AngleFind every continuous hour-and-minute hand solution for a chosen smaller angle in a 12-hour cycle, with precise seconds and hand-position reports.
ConvertersJulian Date & Modified Julian Day ConverterConvert batches of Gregorian UTC dates to Julian dates and Modified Julian dates, or convert decimal Julian dates back to UTC.
Help improve this tool
Report a problem or suggest an improvement
Describe the issue without pasting private tool input. Feedback goes to our admin inbox.