📅 Nth Weekday of Month Calculator
By ToolNimba Editorial Team · Updated 2026-06-19
Pick an occurrence, weekday, month and year to find the date.
This nth weekday calculator finds the exact date of a given weekday in a month, such as the 3rd Monday of January 2026 or the last Friday of November. Choose the occurrence (1st through 5th, or last), the weekday, the month and the year, and the tool returns the date in both long and ISO format. It also tells you when a 5th occurrence does not exist, since some weekdays appear only four times in a given month.
What is the Nth Weekday Calculator?
Many real dates are defined not by a fixed number but by a pattern: the third Monday, the last Thursday, the first Sunday. US Thanksgiving is the fourth Thursday of November, Memorial Day is the last Monday of May, and countless meetings, payroll runs and reports land on the second Tuesday or the last Friday. To turn one of these rules into an actual calendar date you need to know which day of the week the month starts on, and then count forward.
The method is simple once you see it. Find the first occurrence of the chosen weekday in the month, then add seven days for each step beyond it: the second occurrence is seven days after the first, the third is fourteen days after, and so on. To find the first occurrence, look at what weekday the 1st of the month falls on and count forward to the next matching weekday. For the last occurrence, start from the final day of the month and walk backward to the nearest matching weekday.
The one catch is the fifth occurrence. A month has 28 to 31 days, which is four full weeks plus zero to three extra days. So every weekday appears at least four times, but only the weekdays that land on those one to three extra days at the end appear a fifth time. That means a 5th Monday or 5th Saturday exists in some months and not others. This calculator checks the count for you and, when you ask for an occurrence that is not there, says clearly that it does not exist rather than rolling silently into the next month.
When to use it
- Working out fixed-rule holidays like the fourth Thursday of November (US Thanksgiving) or the last Monday of May (Memorial Day).
- Scheduling recurring meetings or reports that fall on the second Tuesday or last Friday of each month.
- Setting payroll, billing or rent dates that are tied to a weekday rather than a fixed number.
- Checking whether a month actually has a 5th Monday (or any 5th weekday) before scheduling something for it.
How to use the Nth Weekday Calculator
- Choose the occurrence you want: 1st, 2nd, 3rd, 4th, 5th, or Last.
- Pick the weekday, from Sunday through Saturday.
- Select the month and enter the year.
- Read off the resulting date in long form and ISO (YYYY-MM-DD) format, or a note if that occurrence does not exist.
Formula & method
Worked examples
Find the 3rd Monday of January 2026.
- 1 January 2026 is a Thursday (weekday 4).
- Monday is weekday 1, so the first Monday = 1 + ((1 − 4 + 7) mod 7) = 1 + 4 = the 5th.
- The 3rd Monday = first + (3 − 1) × 7 = 5 + 14 = the 19th.
- Confirm: 19 January 2026 is indeed a Monday.
Result: The 3rd Monday of January 2026 is Monday, 19 January 2026.
Find the last Friday of February 2026.
- February 2026 has 28 days. 1 February 2026 is a Sunday (weekday 0).
- Friday is weekday 5, so the first Friday = 1 + ((5 − 0 + 7) mod 7) = 1 + 5 = the 6th.
- Count of Fridays = floor((28 − 6) ÷ 7) + 1 = floor(3.14) + 1 = 4, so there are 4 Fridays.
- Last Friday = first + (4 − 1) × 7 = 6 + 21 = the 27th.
Result: The last Friday of February 2026 is Friday, 27 February 2026.
Common fixed-rule dates defined by an nth weekday
| Date rule | Holiday or event |
|---|---|
| 3rd Monday of January | Martin Luther King Jr. Day (US) |
| 2nd Sunday of May | Mother’s Day (US) |
| Last Monday of May | Memorial Day (US) |
| 1st Monday of September | Labor Day (US) |
| 4th Thursday of November | Thanksgiving (US) |
How many times each weekday can appear in a month
| Days in month | Weekdays appearing 5 times | Weekdays appearing 4 times |
|---|---|---|
| 28 days | None | All 7 |
| 29 days | 1 weekday | 6 weekdays |
| 30 days | 2 weekdays | 5 weekdays |
| 31 days | 3 weekdays | 4 weekdays |
Common mistakes to avoid
- Assuming every month has a 5th occurrence. A 28-day February has exactly four of each weekday, so there is no 5th of anything. Even longer months only have a 5th occurrence for the one to three weekdays that land on the extra days. Always check before scheduling for a 5th Monday or similar.
- Confusing the last weekday with the 4th. The last Monday is the 4th Monday only in months where Mondays appear just four times. In a month with five Mondays, the last Monday is the 5th, not the 4th, so use the Last option rather than assuming 4th.
- Off-by-one when counting from the 1st. The nth occurrence adds (n − 1) weeks to the first occurrence, not n weeks. The 1st occurrence adds zero weeks, the 2nd adds one week (seven days), and so on. Adding a full n weeks lands you one occurrence too far.
- Forgetting that the week starts on Sunday here. This tool numbers weekdays with Sunday as 0 through Saturday as 6, matching JavaScript dates. If you think of the week as starting on Monday, double-check you have selected the weekday you actually mean.
Glossary
- Weekday
- A named day of the week, from Sunday through Saturday, regardless of whether it is a working day.
- Occurrence
- Which instance of a weekday within the month you want: the 1st, 2nd, 3rd, 4th, 5th, or the last.
- Nth weekday
- A date defined by a pattern, such as the 3rd Monday, rather than by a fixed day number.
- ISO date
- A date written as YYYY-MM-DD, the international standard format that sorts and parses unambiguously.
- First occurrence
- The earliest date in the month on which the chosen weekday falls, always between the 1st and the 7th.
Frequently asked questions
How do I find the 3rd Monday of a month?
Find the first Monday of the month, which is always between the 1st and the 7th, then add 14 days (two weeks). For example, the first Monday of January 2026 is the 5th, so the 3rd Monday is the 19th. This calculator does the counting for you when you select 3rd, Monday and the month.
Does every month have a 5th weekday?
No. Every weekday appears at least four times, but a 5th occurrence only exists for the one to three weekdays that fall on the extra days past the four full weeks. A 28-day February has no 5th of any weekday at all.
How do I find the last Friday of a month?
Start from the final day of the month and step backward to the nearest Friday. Equivalently, find the first Friday and add seven days for each week until you reach the last one in that month. Select Last and Friday in the tool and it returns the date instantly.
Is the last Monday always the 4th Monday?
Only when the month has exactly four Mondays. If a month has five Mondays, the last Monday is the 5th, not the 4th. Use the Last option to always get the final occurrence regardless of how many there are.
What date is US Thanksgiving each year?
In the United States, Thanksgiving is the fourth Thursday of November. Set the occurrence to 4th, the weekday to Thursday and the month to November, then enter the year to get the exact date for that year.
Why does the tool number Sunday as the start of the week?
It follows the JavaScript convention where Sunday is 0 and Saturday is 6, which keeps the underlying date math reliable. The weekday menu still shows full day names, so you simply pick the day you want without worrying about the numbering.