ISO Week · 2031 · Q4
Week 1
2031 · –
December / January · 4 working days · 2% through 2031
Week 1 of 2031 runs December 30, 2030 to January 5, 2031.
Week 1 starts on Monday, December 30, 2030 and ends on Sunday, January 5, 2031. It's the 364th day of the year, sits in Q4, and falls in December / January. By the end of this week, 5 of 365 days are gone, putting 2031 at 1.4%.
This week includes New Year's Day, so it has 4 working days instead of the usual 5. Need a different week? Browse the full 2031 week calendar, or jump to this week's number.
Week 1 at a glance
The 7 days of week 1
Every date in week 1 of 2031, Monday through Sunday, with day-of-year numbers and events.
| Day | Date | Day no. | Type | Events |
|---|---|---|---|---|
| Monday | Day 364 | Weekday | ||
| Tuesday | Day 365 | Weekday | ||
| Wednesday | Day 1 | Weekday | New Year's Day | |
| Thursday | Day 2 | Weekday | ||
| Friday | Day 3 | Weekday | ||
| Saturday | Day 4 | Weekend | ||
| Sunday | Day 5 | Weekend |
What week 1 of 2031 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 1 is one piece of that system.
In 2031, week 1 covers Dec 30 – Jan 5, 2031. That's December / January, deep in Q4. The same week number shifts by a day or two each year, so week 1 in 2032 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 1 of 2031
🇺🇸 United States
🇨🇦 Canada
🇦🇺 Australia
Week 1 across years
The same ISO week number lands on different dates each year. Here's how week 1 shifts.
| Year | From (Mon) | To (Sun) | Notable | |
|---|---|---|---|---|
| 2028 | view → | |||
| 2029 | New Year's Day | view → | ||
| 2030 | New Year's Day | view → |
Week 1 of 2031: questions and answers
What days are in week 1 of 2031?
Week 1 of 2031 runs from December 30, 2030 (Monday) through January 5, 2031 (Sunday). It spans December / January.
What month is week 1 in 2031?
Week 1 of 2031 spans two months: it starts in December and ends in January 2031.
How many working days are in week 1 of 2031?
Week 1 of 2031 has 4 working days — reduced from 5 due to New Year's Day falling on a weekday.
What week is New Year's Day in 2031?
New Year's Day falls in ISO week 1 of 2031 (Dec 30 – Jan 5, 2031).
What quarter is week 1 of 2031 in?
Week 1 of 2031 is in Q4 (2031). The week starts on day 364 of 365.
What is ISO week 1?
ISO week 1 is defined by the ISO 8601 international standard. It begins on Monday, December 30, 2030, and ends on Sunday, January 5, 2031. It is week 2% through the ISO year 2031.