Birthday of the Heir to the Crown of Tonga is a public holiday in Tonga, known locally as ʻAho ʻAloʻi ʻo e ʻEa ki he Kalauni ʻo Tonga.
In 2026 it falls on Thursday 17 September; in 2027 on Friday 17 September.
The date is fixed, so only the weekday changes from year to year.
Dates, 2025 to 2028
| Year | Date | Weekday | Note |
|---|---|---|---|
| 2025 | 17 September | Wednesday | |
| 2026 | 17 September | Thursday | |
| 2027 | 17 September | Friday long weekend | |
| 2028 | 17 September | Sunday weekend | |
| 2028 | 18 September | Monday long weekend | observed (moved) |