Week 21 of 2026

May 18, 2026 (Monday) to May 24, 2026 (Sunday)

← Week 20 Week 21 of 2026 Week 22 →
ISO Week Number
Week 21
2026 · Week 21 of 53 total weeks

What dates are in Week 21 of 2026?

Week 21 of 2026 runs from May 18, 2026 (Monday) to May 24, 2026 (Sunday). This is the 21th week of the year according to the ISO 8601 standard, in which weeks start on Monday.

Mon
May 18
Day 138
Tue
May 19
Day 139
Wed
May 20
Day 140
Thu
May 21
Day 141
Fri
May 22
Day 142
Sat
May 23
Day 143
Sun
May 24
Day 144
Starts May 18, 2026 Monday · Day 138
Ends May 24, 2026 Sunday · Day 144
Duration 7 days 2026 · 53-week year

📅 Nearby weeks in 2026

Week 19Week 20Week 21Week 22Week 23

📋 All 53 weeks in 2026

12345·678910·1112131415·1617181920·2122232425·2627282930·3132333435·3637383940·4142434445·4647484950·515253

📆 Week 21 in other years

Week 21 · 2025Week 21 · 2027

🔧 Related tools

Week Number Calculator Date to Week 2026 Full Calendar

❓ Related questions about Week 21 of 2026

What day of the week is May 18?

May 18 is a Monday. It is the first day of Week 21 of 2026.

What day of the week is May 24?

May 24 is a Sunday. It is the last day of Week 21 of 2026.

What is the ISO week number for May 18?

May 18 is in Week 21 of 2026 according to ISO 8601.

What is the ISO week number for May 24?

May 24 is in Week 21 of 2026 according to ISO 8601.

❓ Frequently asked questions about Week 21 of 2026

What dates are in Week 21 of 2026?

Week 21 of 2026 runs from May 18, 2026 to May 24, 2026.

Which day of the year does Week 21 start on?

Week 21 of 2026 starts on May 18, 2026, the 138th day of 2026.

Does Week 21 of 2026 fall entirely within 2026?

Yes, all 7 days of Week 21 of 2026 fall within 2026.

How many weeks are in 2026?

2026 has 53 weeks according to ISO 8601.