First read about DATETIMEand TIMESTAMPtype in mysql docs .
Then decide which type of field to use:
, , MySQL , DATETIME.
/ , UTC, TIMESTAMP.
/ VARCHAR.
, , , , , . , . , . , , , . , , , , .
, "1,234" - , 0x04D2 ( 0000 0100 1101 0010 ). "1234" "1,234", , . , , , . .