In Symantec Endpoint Protection Manager (SEPM) 14 RU1, you find that the date-time format of the Network and Exploit Mitigation Attacks report does not correspond to the one you set according to your locale in Home > Preferences > Logs and Reports. Its date-time format is MMDDYY, whereas you specified e.g. DDMMYY. The issue does not occur with other report types.

This issue has been fixed in SEPM 14.2, due to be released in early Q2 2018.