The first type: anyone born after 23 o'clock must change the sun column (that is, the second day of the Gregorian calendar)
The second type: those born within one hour from 23: 00 to 24: 00 (zero o'clock the next day) are counted as "late hours" of the day, and the columns of the day remain unchanged, but the columns of the day adopt the trunk of the next day. For example, the fourteenth day of Jiazi's birth is the late child time, because the normal child time is "no child". After 24 o'clock (zero o'clock the next day), it is no different from the first time.
The above two schools of thought are said to have deep historical origins and astronomical arguments. The second type is also adopted by Wei Zi, which is said to be a calendar habit before the Tang Dynasty (that is, changing the sun column at midnight).
As for which standard to use on the eight characters, it may be necessary to actually check. In the final analysis, the constellation fortune is actually an astronomical solar calendar, which strictly follows the solar terms, and the daily delivery time is equal to deviating from the solar terms; If the date recorded in ancient times is not like the first or second, then it may be inaccurate. This estimate is still inconclusive.