HM Queen Sirikit The Queen Mother's Birthday is a public holiday in Thailand, known locally as วันเฉลิมพระชนมพรรษาสมเด็จพระบรมราชชนนีพันปีหลวง.
In 2026 it falls on Wednesday 12 August; in 2027 on Thursday 12 August.
The date is fixed, so only the weekday changes from year to year.
Dates, 2025 to 2028
| Year | Date | Weekday | Note |
|---|---|---|---|
| 2025 | 12 August | Tuesday | |
| 2026 | 12 August | Wednesday | |
| 2027 | 12 August | Thursday | |
| 2028 | 12 August | Saturday weekend |