When is week 42 of 2026?

Oct 12 – Oct 18

ISO week 42 of 2026

2026

Week details

Oct 12Monday
Oct 18Sunday
53weeks in 2026
11days until it starts
Octoberstarting month
Q4quarter

Week 42 of 2026

ISO week 42 of 2026 starts on Monday, October 12, 2026 and ends on Sunday, October 18, 2026. The year has 53 ISO weeks, so week 42 is week 42 of 53. The week begins in 11 days.

What ISO weeks are

An ISO week always starts on Monday and ends on Sunday. Week 1 is the one that contains the first Thursday of the year, which fixes the count no matter which weekday January 1 falls on. Companies that plan by week number, from shipping to school terms, rely on that consistency so that every planner agrees which dates belong to week 42.

Using week numbers

Quote a week number instead of a date when the exact day is flexible: deliveries expected in week 42, holidays in week 42, or a sprint review in week 42. Check that everyone uses the same system, because some calendars count Sunday as the first day of the week and number the weeks differently. Where in doubt, confirm with the date range shown here.

Nearby weeks

Week 41 ends on Sunday, October 11, 2026, and week 43 starts on Monday, October 19, 2026. Move through the weeks with the links at the bottom of this page.

Today's date at a glance

Today is Thursday, October 1, 2026. That is day 274 of 365 in 2026, in ISO week 40, with 91 days to go before the year ends. The next dates people plan around are Diwali on Saturday, October 10; Columbus Day on Monday, October 12; Halloween on Saturday, October 31. The moon is a Waning Gibbous tonight, with about 75% of its face lit. All of these figures are recalculated when the page loads, so they always describe the day you open it, not the day the page was published.

How the calendar works

The Gregorian calendar has twelve months of 28 to 31 days. A normal year has 365 days and a leap year has 366, with the extra day added to February in every year divisible by four except century years that are not divisible by 400. Because 365 is one more than 52 weeks, most dates move forward one weekday each year and two after a leap day. Weeks are numbered under ISO 8601, which starts weeks on Monday and gives week 1 to the week containing the first Thursday of January.

Frequently asked questions

When does week 42 of 2026 start?

Monday, October 12, 2026.

When does week 42 of 2026 end?

Sunday, October 18, 2026.

How many weeks are in 2026?

53 ISO weeks.

Which month is week 42 in?

It starts in October.

Which quarter is week 42 in?

Quarter 4.

What day does the ISO week start?

Monday.

How many days until week 42?

11 days.

What week is today?

ISO week 40 of 2026.

What is the previous week?

Week 41.

What is the next week?

Week 43.

Does every year have 53 weeks?

No, only some years do.

Can I look up a date instead?

Yes, use the form above.