Source: MIC Tonga:
The other holidays such as Christmas Day, New Year’s Day, Boxing Day, Good Friday and Easter Monday follow the same rule.
Tongan Public Holidays observed every year, in accordance with the provisions of the Public Holiday Act 2010- “Any public holiday that falls upon a Thursday, Friday, Saturday or Sunday- shall be celebrated on the next following Monday- that is, Monday after the date of the Public Holiday. On the other hand, “any public holiday that falls upon a Tuesday or Wednesday- that public Holiday shall be celebrated on the Monday preceding the date of the Public Holiday.”
The main standard Tongan Public Holidays observed every year include: Emancipation Day (June 4); Constitution Day (November 4) and King Tupou I Day (December 4). The actual days on which these days are to be observed will align with the provisions of the amended Public Holidays Act of 2010.
Similarly, the amended Public Holidays Act of 2013 stated that Official birthdays of the Sovereign, His Majesty Tupou VI (July 4) and the Crown Prince of Tonga (September 17) are to be observed on the day it occurs, unless these birthdays fall on Sunday, then the observance of the Public Holiday will be on the Monday after.
An ANZAC Day Dawn Service will commence at 6:00am at the Cenotaph, Pangai Si’i, Nuku’alofa on Saturday 25th April 2015 to mark the 100th anniversary of the Gallipoli landings in Turkey during the WWI.
ANZAC Day commemorates the landing of joint troops of Australian and New Zealand army personnel at Gallipoli and is a national remembrance day for those who served and sacrificed in war, global conflicts and peacekeeping operations.