A customer reported that time would jump forward by an exact number of years on some servers, about once per month. Some dates seen were 2001 , 2004 and 2039 . It was always an exact number of years, sometimes plus exactly one hour. The system error log sys$log.err (below) recorded it as being a requested change, but conlog showed that it was not entered as a console command:

7-25-99 12:24:01 pm: DS-6.0-26
   Severity = 1 Locus = 17 Class = 19
   Directory Services: Local database is open

 7-25-18 4:24:18 pm: SERVER-4.11-2541
   Severity = 0 Locus = 18 Class = 19
   System time changed from file server console. New time is 7-25-2018 5:24:18 pm

The common factor on the servers was that they used an ASUS motherboard, either model psb-d or p2b-ds . The bios versions were 1007 , 1008 and 1009 . On the ASUS website ,http://www.asus.com/Products/Motherboard/bios_slot1.html#p2b-d , there is an update available to a newer Bios version 1010 , which seems to include some y2k fixes and thus perhaps the time issue also.

The assumption has to be that the Bios time jumped forward due to a bug in it, and the server dutifully read the bios time and changed the server time to match, as it is supposed to when a server is a Reference server with Hardware Clock = On .

The message you see when you set the time back to today is "Synthetic Time has been issued" on one or more partitions.