Republic Act No. 4166

: The main purpose of Republic Act No. 4166 is to change the date of Philippine Independence Day from July 4 to June 12 and to declare July 4 as Philippine Republic Day.
: Philippine Independence Day is celebrated on June 12 as per Republic Act No. 4166.
: July 4 is declared as Philippine Republic Day under Republic Act No. 4166.
: Section Twenty-Nine was amended to include June 12 as Independence Day and July 4 as Philippine Republic Day among the legal holidays.
: Thursday and Friday of Holy Week, Christmas Day, and Sundays are considered legal religious holidays.
: The legal holidays are: January 1 (New Year's Day), April 9, May 1 (Labor Day), June 12 (Independence Day), July 4 (Philippine Republic Day), November 30, December 30, the Thursday and Friday of Holy Week, Christmas Day, Sundays, and the day appointed for the general election.
: If a regular holiday of fixed date falls on a Sunday, the next succeeding day shall be observed as a legal holiday.
: RA 4166 took effect upon its approval on August 4, 1964.
: The Senate and House of Representatives of the Philippines in Congress assembled enacted Republic Act No. 4166.
: Filipino citizens are enjoined to observe June 12, Philippine Independence Day, with rites befitting Independence Day.