Week 43 of 2021 runs October 25, 2021 to October 31, 2021.
Week 43 starts on Monday, October 25, 2021 and ends on Sunday, October 31, 2021. It's the 298th day of the year, sits in Q4, and falls in October. By the end of this week, 304 of 365 days are gone, putting 2021 at 83.3%.
This week includes Halloween, Daylight Saving Time — Fall Back, so it has 5 working days instead of the usual 5. Need a different week? Browse the full 2021 week calendar, or jump to this week's number.
Week 43 at a glance
The 7 days of week 43
Every date in week 43 of 2021, Monday through Sunday, with day-of-year numbers and events.
| Day | Date | Day no. | Type | Events |
|---|---|---|---|---|
| Monday | Day 298 | Weekday | ||
| Tuesday | Day 299 | Weekday | ||
| Wednesday | Day 300 | Weekday | ||
| Thursday | Day 301 | Weekday | ||
| Friday | Day 302 | Weekday | ||
| Saturday | Day 303 | Weekend | ||
| Sunday | Day 304 | Weekend | Halloween Daylight Saving Time — Fall Back |
What week 43 of 2021 means
ISO 8601 numbers weeks so every week starts on Monday and ends on Sunday. Week 1 is the one holding the year's first Thursday, which is why early January can land in week 52 or 53 of the previous year. Week 43 is one piece of that system.
In 2021, week 43 covers Oct 25 – Oct 31, 2021. That's October, deep in Q4. The same week number shifts by a day or two each year, so week 43 in 2022 won't share these exact dates. The table below shows how it moves.
Want to check a specific date instead of a week number? The week calculator converts any date to its ISO week. Curious how many weeks a year holds? The weeks in a year guide explains 52 versus 53. And the ISO week number page covers the standard end to end.
Holidays in week 43 of 2021
Week 43 across years
The same ISO week number lands on different dates each year. Here's how week 43 shifts.
| Year | From (Mon) | To (Sun) | Notable | |
|---|---|---|---|---|
| 2024 | view → |
Week 43 of 2021: questions and answers
What days are in week 43 of 2021?
Week 43 of 2021 runs from October 25, 2021 (Monday) through October 31, 2021 (Sunday). It spans October.
What month is week 43 in 2021?
Week 43 of 2021 falls entirely in October 2021.
How many working days are in week 43 of 2021?
Week 43 of 2021 has 5 working days.
What week is Halloween in 2021?
Halloween falls in ISO week 43 of 2021 (Oct 25 – Oct 31, 2021).
What quarter is week 43 of 2021 in?
Week 43 of 2021 is in Q4 (2021). The week starts on day 298 of 365.
What is ISO week 43?
ISO week 43 is defined by the ISO 8601 international standard. It begins on Monday, October 25, 2021, and ends on Sunday, October 31, 2021. It is week 83% through the ISO year 2021.