Week 52, 2027
December 27, 2027 – January 2, 2028
Monday December 27 – Sunday January 22027-W52Days 361–2 (365 → 1)
The seven days
| Date | ISO week date | Day of year | US week | Islamic date (computed) | Holidays and other dates |
|---|---|---|---|---|---|
| Mon, Dec 27 | 2027-W52-1 | 361 | 53 | 29 Rajab 1449 AH | Christmas Day (substitute day) (UK: England and Wales, UK: Scotland, UK: Northern Ireland); Christmas Day (additional day) (Australia: New South Wales, Australia: Queensland, Australia: Western Australia); Christmas Day (Mondayised) (New Zealand); Day of Goodwill (substitute day) (South Africa); The first weekday after Christmas Day (Hong Kong) |
| Tue, Dec 28 | 2027-W52-2 | 362 | 53 | 30 Rajab 1449 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) |
| Wed, Dec 29 | 2027-W52-3 | 363 | 53 | 1 Sha'ban 1449 AH | |
| Thu, Dec 30 | 2027-W52-4 | 364 | 53 | 2 Sha'ban 1449 AH | |
| Fri, Dec 31 | 2027-W52-5 | 365 | 53 | 3 Sha'ban 1449 AH | New Year's Day (observed) (United States (federal)); New Year’s Eve |
| Sat, Jan 1, 2028 | 2027-W52-6 | 001 | 1 | 4 Sha'ban 1449 AH | New Year's Day (11 sets); The first day of January (Hong Kong) |
| Sun, Jan 2, 2028 | 2027-W52-7 | 002 | 2 | 5 Sha'ban 1449 AH |
About week 52
Week 52 straddles New Year: it begins in 2027 and ends in 2028, and under ISO 8601 all seven days belong to week 52 of 2027, even the days of January 2028. It is the last ISO week of 2027; week 1 of 2028 starts on Monday, January 3, 2028. In US numbering, where weeks start on Sunday and the week of January 1 is week 1, Monday to Friday are US week 53 of 2027, Saturday US week 1 of 2028, and Sunday US week 2 of 2028.
Holidays this week: Christmas Day (substitute day) on Mon, Dec 27 in UK: England and Wales, UK: Scotland, UK: Northern Ireland; Christmas Day (additional day) on Mon, Dec 27 in Australia: New South Wales, Australia: Queensland, Australia: Western Australia; Christmas Day (Mondayised) on Mon, Dec 27 in New Zealand; Day of Goodwill (substitute day) on Mon, Dec 27 in South Africa; The first weekday after Christmas Day on Mon, Dec 27 in Hong Kong; Boxing Day (substitute day) on Tue, Dec 28 in UK: England and Wales, UK: Scotland, UK: Northern Ireland; Boxing Day (additional day) on Tue, Dec 28 in Australia: New South Wales, Australia: Queensland, Australia: Western Australia; Boxing Day (Mondayised) on Tue, Dec 28 in New Zealand; New Year's Day (observed) on Fri, Dec 31 in United States (federal); New Year's Day on Sat, Jan 1 in 11 of the countries and regions we cover; The first day of January on Sat, Jan 1 in Hong Kong. 1 Sha'ban 1449 AH falls on Wed, Dec 29 by the Umm al-Qura calendar (computed). Also this week: New Year’s Eve on Fri, Dec 31 (December 31). All weeks of 2027 lists the neighbouring weeks.
Week 52 in other years
| Year | Week 52 runs |
|---|---|
| 2025 | Mon, Dec 22 – Sun, Dec 28 |
| 2026 | Mon, Dec 21 – Sun, Dec 27 |
| 2027 | Mon, Dec 27 – Sun, Jan 2, 2028 |
| 2028 | Mon, Dec 25 – Sun, Dec 31 |
| 2029 | Mon, Dec 24 – Sun, Dec 30 |
| 2030 | Mon, Dec 23 – Sun, Dec 29 |
In 2028, week 52 runs Mon, Dec 25 – Sun, Dec 31: 364 days later, 2 days earlier in the calendar. Over the 400-year cycle, the Monday of week 52 falls between December 20 and December 27.
By the end of week 52, 365 days of 2027 have passed (100.0% of the year). The week falls in Q4.
Writing week 52
ISO 8601 writes this week as 2027-W52 (basic format 2027W52), from 2027-W52-1 on Monday to -7 on Sunday. The week number page shows the spreadsheet and Python formulas that give these numbers.