If the time loss is most serious when the system is on, check the Device Manager for conflicts or disabled devices. (The clock is interrupt-driven, and conflicting devices or software can impair its operation.)
The RTC(real time clock chip) may be faulty. If so, usually aint worth the $ to rplace it. If it really bothers you, replace the mobo.............
Using a time synchronizing program may alleviate some of the trouble........