The Philippines: time zone history, and your birth hour
The clocks in the Philippines have changed 12 times since 1900. Today they run on UTC+8; the last change was on 28 Jul 1990. A calculator that uses today’s offset for every birth is out by some minutes for anyone born in any of the different eras below.
Since 1925, the widest gap is the summer time from 1936: 60 minutes, enough to move about 50% of births into a different two-hour period.
Every era
| From – to | Clock | Versus today · births in another hour |
|---|---|---|
| 1 Jan 1900 – 1 Nov 1936 | UTC+8 standard time | same |
1936–1942, 2 stretcheseach stretch
| UTC+9 in summer, UTC+8 the rest of the year | up to 60 min about 50% |
| 12 Feb 1942 – 4 Mar 1945 | UTC+9 wartime, on Tokyo time | +60 min about 50% |
| 4 Mar 1945 – 30 Nov 1945 | UTC+9 summer time | +60 min about 50% |
| 30 Nov 1945 – 12 Apr 1954 | UTC+8 standard time | same |
1954–1990, 3 stretcheseach stretch
| UTC+9 in summer, UTC+8 the rest of the year | up to 60 min about 50% |
| 28 Jul 1990 – today | UTC+8 standard time | same |
The second figure in each row is the births moved into another two-hour period: about m/120 of them when the clock is m minutes out. For Kuala Lumpur, 30 minutes out from 1946 to 1981, the measured share is 26.0% of 4,000 sampled births.
Born in summer time?
In each of these, the clocks ran ahead of standard time. A birth inside one happened that much earlier by the sun than the clock said; give the birthplace and this site’s calculator takes it off for you.
- From 28 Mar 1977, 00:00 to 22 Sep 1977, 00:00 · 60 minutes ahead
- From 21 May 1990, 00:00 to 29 Jul 1990, 00:00 · 60 minutes ahead
Times are on the local clock: when each began the clocks went forward, and when it ended they went back.