Week 53, 2026
December 28, 2026 – January 3, 2027
Monday December 28 – Sunday January 32026-W53Days 362–3 (365 → 1)
The seven days
| Date | ISO week date | Day of year | US week | Islamic date (computed) | Holidays and other dates |
|---|---|---|---|---|---|
| Mon, Dec 28 | 2026-W53-1 | 362 | 53 | 19 Rajab 1448 AH | Boxing Day (substitute day) (UK: England and Wales, UK: Scotland, UK: Northern Ireland); Boxing Day (additional day) (Australia: New South Wales, Australia: Queensland, Australia: Western Australia); Boxing Day (Mondayised) (New Zealand) |
| Tue, Dec 29 | 2026-W53-2 | 363 | 53 | 20 Rajab 1448 AH | |
| Wed, Dec 30 | 2026-W53-3 | 364 | 53 | 21 Rajab 1448 AH | |
| Thu, Dec 31 | 2026-W53-4 | 365 | 53 | 22 Rajab 1448 AH | New Year’s Eve |
| Fri, Jan 1, 2027 | 2026-W53-5 | 001 | 1 | 23 Rajab 1448 AH | New Year's Day (16 sets); The first day of January (Hong Kong) |
| Sat, Jan 2, 2027 | 2026-W53-6 | 002 | 1 | 24 Rajab 1448 AH | |
| Sun, Jan 3, 2027 | 2026-W53-7 | 003 | 2 | 25 Rajab 1448 AH |
About week 53
Week 53 straddles New Year: it begins in 2026 and ends in 2027, and under ISO 8601 all seven days belong to week 53 of 2026, even the days of January 2027. It is the last ISO week of 2026, one of the rare week 53s: 2026 has 53 weeks; week 1 of 2027 starts on Monday, January 4, 2027. In US numbering, where weeks start on Sunday and the week of January 1 is week 1, Monday to Thursday are US week 53 of 2026, Friday and Saturday US week 1 of 2027, and Sunday US week 2 of 2027.
Holidays this week: Boxing Day (substitute day) on Mon, Dec 28 in UK: England and Wales, UK: Scotland, UK: Northern Ireland; Boxing Day (additional day) on Mon, Dec 28 in Australia: New South Wales, Australia: Queensland, Australia: Western Australia; Boxing Day (Mondayised) on Mon, Dec 28 in New Zealand; New Year's Day on Fri, Jan 1 in 16 of the countries and regions we cover; The first day of January on Fri, Jan 1 in Hong Kong. Also this week: New Year’s Eve on Thu, Dec 31 (December 31). All weeks of 2026 lists the neighbouring weeks.
Week 53 in other years
| Year | Week 53 runs |
|---|---|
| 2026 | Mon, Dec 28 – Sun, Jan 3, 2027 |
Over the 400-year cycle, the Monday of week 53 falls between December 27 and December 28. 2024, 2025, 2027, 2028 and 2029 have no week 53, because only years whose January 1 is a Thursday (or a Wednesday in a leap year) have 53 weeks.
By the end of week 53, 365 days of 2026 have passed (100.0% of the year). The week falls in Q4.
Writing week 53
ISO 8601 writes this week as 2026-W53 (basic format 2026W53), from 2026-W53-1 on Monday to -7 on Sunday. The week number page shows the spreadsheet and Python formulas that give these numbers.