2018-05-12 6:45 GMT+08:00 Kalin KOZHUHAROV <me.kalin@gmail.com>:
> I only see 2 ways:
> * hardware: add a cheap RTC (best), or storage (USB, SD)
> * policy: add exception for ntpdate on base UDP (not WG) (or have
> dedicated server/s for that, which you control).

As Kalin's suggestion, I think policy routing, or plain static route, is
the easier
solution.

You can point ntpdate or ntpd to a fixed ntp server, and add a rule or more
specific staticr oute for this fixed server.

Or, if you have a running computer in your local net, use that computer as
one of ntp servers.