Your Thai Astrology Birth Day: Before 06:00 Is the Previous Day
Explains the two rules that make your birth day in Thai astrology differ from the calendar day, with example birth times to watch out for and what to do if you do not know your time of birth.
Published 30 September 2026
Contents
Your calendar birth day and your Thai astrology birth day may differ
Everything in Taksa (ทักษา) starts from your birth day. If the birth day is wrong, the whole table of fortune-boosting numbers and Kalakini (กาลกิณี) is wrong too. Most people use the day of the week from the calendar, which mostly matches Thai astrology, but there are two cases where it does not, and these two cases are more common than you might think for people born late at night or before dawn.
This article explains both rules and includes an example table generated by the same function as this site's birth-day lucky number page, so you can compare it with your own case.
Rule one: born before 06:00 counts as the previous day
Thai astrology holds that a new day begins at dawn, which this site sets at 06:00. People born after midnight up to 05:59 are therefore counted as born on the previous day. For example, someone born at 03:00 on a calendar Thursday is considered born on Wednesday.
After shifting the day, you still need to check rule two, because if the shifted day is a Wednesday, the result is Wednesday night, not Wednesday daytime.
Rule two: Wednesday splits into daytime and night
Wednesday is the only day split in two. From 06:00 to 17:59 is Wednesday daytime, which uses Mercury, number 4. From 18:00 until 05:59 the next morning is Wednesday night, which uses Rahu, number 8. The Taksa tables for these two are different sets, including their Kalakini.
Some schools divide daytime from night at exactly 18:00, while others draw the line one minute differently. If you were born very close to this time, check both versions and choose a plate that does not hit the Kalakini of either case.
Examples to watch out for
The table below shows example birth dates and times. Note three points. First, someone born on a Wednesday at 05:00 gets Tuesday, not Wednesday. Second, someone born on a Thursday at 05:00 gets Wednesday night. Third, 17:59 and 18:00 on a Wednesday give different results.
The examples use the year 2000 because its days of the week are easy to see, but the rules apply to every year.
| Calendar date and time of birth | Calendar day of the week | Thai astrology birth day |
|---|---|---|
| 5 Jan 2000, 12:00 | Wednesday | Wednesday (daytime) |
| 5 Jan 2000, 17:59 | Wednesday | Wednesday (daytime) |
| 5 Jan 2000, 18:00 | Wednesday | Wednesday (night) |
| 5 Jan 2000, 05:00 | Wednesday | Tuesday |
| 6 Jan 2000, 05:00 | Thursday | Wednesday (night) |
| 1 Jan 2000, 05:59 | Saturday | Friday |
| 1 Jan 2000, 06:00 | Saturday | Saturday |
What to do if you do not know your time of birth
If you do not know your time of birth, this site assumes you were born during the day and says so in the confirmation message. If you were born on a Wednesday, check both Wednesday daytime and Wednesday night, then choose a plate that does not hit the Kalakini of either. For people born on other days who do not know the time, the result is only off if they were born before 06:00, which counts as the previous day.
If you want to know your exact time of birth, the document the hospital issued at your birth usually records it, or you can ask older family members who remember. The date and time of birth you enter on the birth-day lucky number page are calculated only on your own device and are not sent to the server.
Numbers mentioned in this article
FAQ on this topic
I was born at 05:00 on a Saturday. Which day counts as my birth day?
It counts as Friday. Because you were born before 06:00, Thai astrology counts it as the previous day.
I was born on a Wednesday at exactly 06:00. Is that daytime or night?
This site treats it as Wednesday daytime, because 06:00 is when the new day begins, and Wednesday night starts from 18:00. Some schools draw the line slightly differently, so if you were born close to this time, check both versions.
Why is Wednesday the only day split into daytime and night?
The Taksa texts hold that from 18:00 until dawn, Wednesday is under the influence of Rahu, so it is split in two. Other days have no such rule.
Read next
Numerology readings are a matter of personal belief. Please use your own judgement. They are not a guarantee of any outcome.