A calendar date entered in data base format gives the Gym-ID.
The Gym-ID is the HEX form of that YYYYMMDD DEC data base format date.
Years must be in YYYY form.
Months need leading Zeros and are 1...12.
Auxiliary months may be 13...24 / 25...36 / 37...48 / 49...60 / 61...72 / 73...84 / 85...96.
Days need leading Zeros and are 0...31.
Auxiliary days can be 32, 33, 34...66 / 67...99.