Fix broken clock on NAS

Hi, I have a installing with FreeRADIUS and Chilli/Cova Hotspot. Everything works good so far, just some NAS (Openmesh hardware mostly) appears with date time about 1970. Also, FreeRADIUS is running with MYSQL backend. I know FreeRADIUS uses TimeStamp attribute for accounting, but I don't find a way to resolve broken clock on NAS. Furthermore, I'm pretty sure clock on NAS is update. Anyone knows how I could solve this? Best regards. Thanks. David L.