Week 21 in 1980
Week 21 of 1980 begins on May 19, 1980 and ends on May 25, 1980. It covers days 140 to 146 of the year and falls in quarter 2.
Weeks since this week: 2420
Week 21 of 1980 at a glance
| Starts (Monday) | May 19, 1980 |
|---|---|
| Ends (Sunday) | May 25, 1980 |
| US week (Sunday to Saturday) | 21 (May 18, 1980) |
| Month | May |
| Quarter | Q2 |
| Days of the year | 140–146 |
| Year completed at the end of this week | 39.9% |
| Weeks left in 1980 after this week | 31 |
| Weeks in 1980 | 52 |
| Even or odd week | Odd |
Calendar for May 1980
Download Calendar in printable A4 PDF
(US version) (EU/ISO Version)
All Weeks in 1980:
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 1980. It runs from May 18, 1980 to May 24, 1980.
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 1978 | May 22, 1978 | May 28, 1978 |
| Week 21 in 1979 | May 21, 1979 | May 27, 1979 |
| Week 21 in 1981 | May 18, 1981 | May 24, 1981 |
| Week 21 in 1982 | May 24, 1982 | May 30, 1982 |
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 1980 began on December 31, 1979. 1980 has 52 ISO weeks.
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 1980 start and end?
Week 21 of 1980 starts on May 19, 1980 and ends on May 25, 1980 (ISO 8601, Monday to Sunday).
Which month is week 21 of 1980 in?
Week 21 of 1980 is in May.
What dates are in week 21 of 1980?
May 19, 1980, May 20, 1980, May 21, 1980, May 22, 1980, May 23, 1980, May 24, 1980, and May 25, 1980
How many weeks does 1980 have?
1980 has 52 ISO weeks.
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 1980. It runs from May 18, 1980 to May 24, 1980.