Assuming that your hardware clock stays up to date you can do the following.
If TIMESYNC.CFG is set to "hardware clock = on" it will reset to the hardware clock which is not losing time.
The otherkiwi's idea of setting the NTP time source to a source on the Internet will be your most reliable. Also if you have several servers geographically dispersed you should use the model of Reference-Primary-secondary. You can point the Reference to a time source on the Internet then all of your WS and servers will be up to date.
Below is an example of what the config for the reference server would look like,
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Default Time Server Type: Reference
TIMESYNC Configured Sources: On
TIMESYNC Time Sources: 192.6.38.127:123; 204.152.184.72:123;
To configure see the following support articles,
TID10050215, TID10070057, TID10060982,