Start date or End date of License on SEPM console is different from those in lincense file (.slf).
For example, following is data in .slf file:
start_date 2017-06-07
end_date 2019-06-06
If you install this license on SEPM, start/end date on SEPM console - [Admin] - [Licenses] shows following,
Start date 6/6/2017
Expiration date 6/6/2019
This issue is fixed in Symantec Endpoint Protection 14.2 RU1. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.