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Twelve Years of Daylight Saving Time
— When Your Hour Pillar Shifts by One
If you were born in summer in 1948–51, 1955–60 or 1987–88,
the clock was 1 hour ahead.
Without correction, your hour pillar shifts by one
Korea has observed daylight saving time too — for twelve years, no less. Many people only remember it being used for the broadcast schedule of the 1988 Seoul Olympics, but there were two earlier periods.
If you were born during those periods, the time on your birth record is one hour ahead of the actual sun. In Saju, the hour pillar is set by the sun's position, so entering it as is gives the wrong result.
In this article 7 topics
When was it observed?
Below are the actual periods it was in effect, based on the days clocks were moved forward and set back.
| Year | Start | End | Notes |
|---|---|---|---|
| 1948 | 6/1 | September 12 | Right after the government was established |
| 1949 | April 3 | September 10 | |
| 1950 | 4/1 | September 9 | |
| 1951 | 5/6 | September 8 | Last year of the first period |
| — Not observed in 1952–1954 — | |||
| 1955 | May 5 | September 8 | This period overlaps with the 127.5°E standard time |
| 1956 | May 20 | September 29 | |
| 1957 | May 5 | September 21 | |
| 1958 | May 4 | September 20 | |
| 1959 | May 3 | September 19 | |
| 1960 | 5/1 | September 17 | |
| — Not observed in 1961–1986 — | |||
| 1987 | May 10 | October 11 | Ahead of the Seoul Olympics |
| 1988 | May 8 | October 9 | |
Korea hasn't observed daylight saving time since it ended on October 9, 1988. So if you were born in 1989 or later, this correction doesn't apply to you.
Does one hour really make that much difference?
The hour pillar is divided into two-hour slots. So a one-hour difference crosses into another slot half the time.
| Hour branch | Time range | Hour branch | Time range |
|---|---|---|---|
| Ja (子) | 23:00 ~ 00:59 | O (午) | 11:00 ~ 12:59 |
| Chuk (丑) | 01:00 ~ 02:59 | Mi (未) | 13:00 ~ 14:59 |
| In (寅) | 03:00 ~ 04:59 | Sin (申) | 15:00 ~ 16:59 |
| Myo (卯) | 05:00 ~ 06:59 | Yu (酉) | 17:00 ~ 18:59 |
| Jin (辰) | 07:00 ~ 08:59 | Sul (戌) | 19:00 ~ 20:59 |
| Sa (巳) | 09:00 ~ 10:59 | Hae (亥) | 21:00 ~ 22:59 |
If the recorded time is near an odd hour on the dot, subtracting one hour moves you into a different slot. For example, a birth recorded at 3 p.m. on August 15, 1988 becomes 2 p.m. after correction. That's a move from Sin (申) to Mi (未), and both characters of the hour pillar change entirely.
Two corrections apply for 1955–1960
In this period, daylight saving time overlaps with the 127.5°E standard time. Both corrections must be applied.
| Step | Correction | Example: 9 a.m., June 10, 1958 |
|---|---|---|
| Recorded time | — | 09:00 |
| Daylight saving time | −60 min | 08:00 |
| 127.5°E → 135°E | +30 min | 08:30 |
| Result | Total −30 min | Jin (辰) hour — calculated without correction, it would be the Sa (巳) hour |
If you apply only one correction, or none at all, the hour pillar of people born in this period comes out wrong. Why the standard time was 127.5°E is explained in Korea's standard time changed three times.
When reading your parents' or grandparents' Saju
The people who actually need this correction are usually the generation above you rather than yourself. Someone born in 1948–1960 is likely a parent or grandparent, and someone born in 1987–1988 is now in their late 30s.
If you add family members to an app to view together and this isn't handled automatically, you'll get readings based on the wrong Saju. In Mutal Unnie's Manseryeok calculator, when you turn on the daylight saving correction, it checks whether the date falls in the period, applies the correction and tells you on screen what it corrected. The app calculates using the clock time you enter as is.
When the daylight saving record itself is unclear
To be honest, birth records from this era often have inaccurate times to begin with.
- It was common to register a birth days or even months late
- Clocks were scarce, so many people remember times like “around sunrise” or “around lunchtime”
- It's also unclear whether a time remembered that way was based on a daylight-saving clock or on the sun
“You were born when the sun was high in the sky” is actually sun-based testimony, so it doesn't need a daylight saving correction. On the other hand, “the wall clock struck three” is clock-based, so it does need correcting. If you can't tell which, it's better to look at both results and see which seems more plausible. If you don't know the time at all, see When you don't know your birth time.
Don't enter an unknown time at random. A Saju with the wrong hour pillar is worse than a Three Pillars (三柱) reading without the hour. Reading without the information is more accurate than making it up.
Check it yourself
Enter your date and time of birth, and it automatically checks whether it falls in a daylight saving period and shows the result before and after correction.
→ Open the Manseryeok calculator
You can view your family's Saju too
Add your parents or grandparents and the corrections are handled for you. Adding someone requires their consent.
Get the app for iPhone & AndroidFAQ
When did Korea observe daylight saving time?
In three periods, twelve years in all: four years in 1948–1951, six years in 1955–1960, and two years in 1987–1988 ahead of the Seoul Olympics. The last day was October 9, 1988.
How does being born during daylight saving time change your Saju?
You need to subtract 1 hour from the recorded time to get the actual sun-based time. Each hour branch covers two hours, so if the recorded time is near an odd hour on the dot, both characters of the hour pillar change entirely.
I was born in August 1988. Does daylight saving time apply to me?
Yes, it does. In 1988 it ran from May 8 to October 9, so all of August is included. In 1987 it ran from May 10 to October 11.
Do two corrections apply for 1955–1960?
That's right. Daylight saving time (−60 minutes) and the 127.5°E standard time (+30 minutes) overlap, so the net result is that you subtract 30 minutes from the recorded time.