Week 39, 2027
September 27 – October 3, 2027
Monday September 27 – Sunday October 32027-W39Days 270–276
The seven days
| Date | ISO week date | Day of year | US week | Islamic date (computed) | Holidays and other dates |
|---|---|---|---|---|---|
| Mon, Sep 27 | 2027-W39-1 | 270 | 40 | 26 Rabi' al-Thani 1449 AH | King's Birthday (Australia: Western Australia) |
| Tue, Sep 28 | 2027-W39-2 | 271 | 40 | 27 Rabi' al-Thani 1449 AH | |
| Wed, Sep 29 | 2027-W39-3 | 272 | 40 | 28 Rabi' al-Thani 1449 AH | |
| Thu, Sep 30 | 2027-W39-4 | 273 | 40 | 29 Rabi' al-Thani 1449 AH | National Day for Truth and Reconciliation (Canada (federal)) |
| Fri, Oct 1 | 2027-W39-5 | 274 | 40 | 1 Jumada al-Ula 1449 AH | National Day (Hong Kong) |
| Sat, Oct 2 | 2027-W39-6 | 275 | 40 | 2 Jumada al-Ula 1449 AH | Rosh Hashanah 5788 |
| Sun, Oct 3 | 2027-W39-7 | 276 | 41 | 3 Jumada al-Ula 1449 AH |
About week 39
The week spans two months: it starts in September and ends in October, with October 1 on Friday, the first day of Q4. In US numbering, where weeks start on Sunday and the week of January 1 is week 1, Monday to Saturday are US week 40 and Sunday US week 41.
Holidays this week: King's Birthday on Mon, Sep 27 in Australia: Western Australia; National Day for Truth and Reconciliation on Thu, Sep 30 in Canada (federal); National Day on Fri, Oct 1 in Hong Kong. On Sun, Oct 3 clocks in South-east Australia (Sydney, Melbourne) go forward one hour at 2:00 a.m. 1 Jumada al-Ula 1449 AH falls on Fri, Oct 1 by the Umm al-Qura calendar (computed). Also this week: Rosh Hashanah 5788 on Sat, Oct 2 (Jewish New Year, 1 Tishrei; begins at sunset the evening before). All weeks of 2027 lists the neighbouring weeks.
Week 39 in other years
| Year | Week 39 runs |
|---|---|
| 2025 | Mon, Sep 22 – Sun, Sep 28 |
| 2026 | Mon, Sep 21 – Sun, Sep 27 |
| 2027 | Mon, Sep 27 – Sun, Oct 3 |
| 2028 | Mon, Sep 25 – Sun, Oct 1 |
| 2029 | Mon, Sep 24 – Sun, Sep 30 |
| 2030 | Mon, Sep 23 – Sun, Sep 29 |
In 2028, week 39 runs Mon, Sep 25 – Sun, Oct 1: 364 days later, 2 days earlier in the calendar. Over the 400-year cycle, the Monday of week 39 falls between September 20 and September 27.
By the end of week 39, 276 days of 2027 have passed (75.6% of the year), and 13 ISO weeks of 2027 remain. The week falls in Q3.
Writing week 39
ISO 8601 writes this week as 2027-W39 (basic format 2027W39), from 2027-W39-1 on Monday to -7 on Sunday. The week number page shows the spreadsheet and Python formulas that give these numbers.