Firstly, there is no guarantee that a PCs realtime clock (RTC) will be accurate. Some RTCs run fast, others run slow - this is partly the reason why Microsoft provides time synching as part of their OS.
Secondly, you can change the polling interval used by Windows to synch the time with a time server. The standard interval is 7 days (604800 seconds) but you can select another interval, 15 mins (900 secs) being a recommended minimum. This value is set in the Registry.
If you have experience with editing Registry values the relevant key is:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpClient\SpecialPollInterval