How to use the nth weekday of month calculator
- Pick which one you want, such as First, Third or Last, then the weekday.
- Choose the month and enter the year.
- Or use a preset button for a common date such as Thanksgiving or Memorial Day.
- Read the date, the day of the week and the table showing the same rule in all twelve months of that year.
Formula
First weekday = 1 + (target weekday - weekday of the 1st + 7) mod 7
Nth weekday = first weekday + (n - 1) x 7, if it is within the month
Last weekday = last day of the month - (weekday of the last day - target weekday + 7) mod 7
A fifth weekday exists only when the month has at least 29 days and starts on a suitable weekday. Otherwise the tool says it does not exist.
Worked example
The fourth Thursday of November 2026 is November 26, which is Thanksgiving in the United States. The last Monday of May 2026 is May 25, Memorial Day, and the first Monday of September 2026 is September 7, Labor Day.
Martin Luther King Jr. Day, the third Monday of January 2026, falls on January 19, and Mother's Day, the second Sunday of May, on May 10. A fifth Monday of February 2026 does not exist, and the tool says so instead of rolling into March.
Why dates like this move
Many holidays, meetings and events are defined by a weekday and a position in the month, so the date changes each year. Payroll, school boards, trash pickup and clubs often use the same rule. Looking up the whole year in the table makes it easy to put every occurrence on a calendar.
First, second, third, fourth, fifth and last
Fourth and last often give different dates. In a month with five of a weekday, the last one is the fifth, and in a month with four, the last is the fourth. That is why Thanksgiving, set as the fourth Thursday, is the last Thursday of November in some years and not in others. Use the day of the week calculator to check any single date.
Planning with the result
Once you have a date, count the days to it with the date calculator, see the week number with the week number calculator, or count working days with the business days calculator.
Assumptions and limits
- Dates use the Gregorian calendar, from 1583 to 9999.
- Weeks start on Sunday in the weekday list, which does not affect the result.
- The presets show the rule for the holiday in the United States. Observed holidays that move to a Friday or Monday are not modeled.
- A date that does not exist, such as a fifth weekday in a short month, is reported as such and not adjusted.
Frequently asked questions
What is the third Monday of the month?
It is the Monday on day 15 to 21 of that month. The calculator finds the exact date for any month and year.
When is Thanksgiving?
In the United States it is the fourth Thursday of November. In 2026 that is November 26.
How do I find the last Friday of a month?
Count back from the last day of the month to the nearest Friday. Choose Last and Friday in the tool to get the date without counting.
Why does the fifth weekday sometimes not exist?
A month has four full weeks plus zero to three extra days. Only the weekdays that fall in those extra days occur five times.