Storing Last Login Plugin value in SQL

[dovecot at ptld.com]

The last-login plugin sends a number (epoch seconds) as uint or string 
in a query to sql. If i create a column type in sql of varchar() the 
number is saved in the column as a string, but not very useful.

I can not figure out how to get that value into a date/time column such 
as date, datetime or timestamp. All three cause an error of Incorrect 
datetime value: '1631556506' for column.

Anyone have any idea how to get the last-login plugin to update a 
date/time column in sql?