Understanding the PERSONAL_ID concept and birthday management

PERSONAL_ID refers to a specific value assigned to people in Slovakia and the Czech Republic. It is a unique personal identification number formed of the person’s date of birth, gender, and a terminal number, which is a differentiating number for people born on the same day. In total, it consists of six digits followed by the slash symbol and another four digits.

The first two digits of PERSONAL_ID are the last two digits of the person’s year of birth. The second two digits express the numeric designation of the person’s month of birth (the value is increased by 50 for women). The third two-digit set represents the numerical designation of the person’s day of birth. This is an example of a man and woman:

--> 90 06 23 / 1234				90 56 23 / 1239
--> MAN						WOMAN
--> Year = 90					Year = 90
--> Month = 6					Month = 6
--> Day = 23					Day = 23

The whole personal identifier...