UPMT .. how to read it?

sorry for simple question.  I have to write a SQL to return data that created in last 15 minutes from a table.  I plan to use UPMT column in my where clause.

I was told as below :

assume UPMJ is 7/1/2020

UPMT        Action time

--------         ------------------

1               7/1/2020    00:00:01

18            7/1/2020     00:00:18

828           7/1/2020    08:28:00

1408         7/1/2020   14:08:00

10321       7/1/2020    01:03:21

100002      7/1/2020   10:00:02

are they correct?

any suggestion how the where clause should look like?  I am in DB2