Week 21 in 2561
Week 21 of 2561 begins on May 18, 2561 and ends on May 24, 2561. It covers days 138 to 144 of the year and falls in quarter 2.
Weeks until this week: 27896
Week 21 of 2561 at a glance
| Starts (Monday) | May 18, 2561 |
|---|---|
| Ends (Sunday) | May 24, 2561 |
| US week (Sunday to Saturday) | 21 (May 17, 2561) |
| Month | May |
| Quarter | Q2 |
| Days of the year | 138–144 |
| Year completed at the end of this week | 39.5% |
| Weeks left in 2561 after this week | 32 |
| Weeks in 2561 | 53 |
| Even or odd week | Odd |
Calendar for May 2561
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(US version) (EU/ISO Version)
All Weeks in 2561:
Past & Future Week Number 21:
US and ISO week numbers
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 21 of 2561. It runs from May 17, 2561 to May 23, 2561.
Even and odd weeks
Week 21 is an odd week. Even and odd week numbers are used for alternating schedules such as shift rotas, school timetables, custody arrangements and waste collection.
Week 21 in other years
| From | To | |
|---|---|---|
| Week 21 in 2559 | May 21, 2559 | May 27, 2559 |
| Week 21 in 2560 | May 19, 2560 | May 25, 2560 |
| Week 21 in 2562 | May 24, 2562 | May 30, 2562 |
| Week 21 in 2563 | May 23, 2563 | May 29, 2563 |
How week numbers are counted
Most of the world numbers weeks according to the ISO 8601 standard. A week starts on Monday, and week 1 is the week that contains the first Thursday of the year, which is always the week that contains 4 January.
Week 1 of 2561 began on December 29, 2560. 2561 has 53 ISO weeks, because 1 January 2561 falls on a Thursday.
Because of this rule, the first days of January can belong to the last week of the previous year, and the last days of December can belong to week 1 of the next year.
In the United States, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the US week number can differ from the ISO week number.
Find the week number of a date
Frequently Asked Questions (FAQ)
When does week 21 of 2561 start and end?
Week 21 of 2561 starts on May 18, 2561 and ends on May 24, 2561 (ISO 8601, Monday to Sunday).
Which month is week 21 of 2561 in?
Week 21 of 2561 is in May.
What dates are in week 21 of 2561?
May 18, 2561, May 19, 2561, May 20, 2561, May 21, 2561, May 22, 2561, May 23, 2561, and May 24, 2561
How many weeks does 2561 have?
2561 has 53 ISO weeks, because 1 January 2561 falls on a Thursday.
Is week 21 an even or odd week?
Week 21 is an odd week.
What is the US week number for this week?
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 21 of 2561. It runs from May 17, 2561 to May 23, 2561.