Year_2038_problem
https://en.wikipedia.org/wiki/Year_2038_problem
mysql - DATETIME VS INT for storing time? - Stack Overflow https://stackoverflow.com/questions/43705935/datetime-vs-int-for-storing-time
MySQL :: Re: DATETIME vs. INT(11)? https://forums.mysql.com/read.php?10,276287,276407#msg-276407