Brian Gaff a écrit :
Chuckle. I do hope so.
However, I often have a laugh at the difference in time between radio
controlled clock, DAB clock and the internet bassed one on the pc.
Several seconds quite often. Who is right?
I also have a phone which every so often moves an hour backwards for no
apparent reason.

My (RC) watch, RC clocks, phone and computers time are always in sync,
unless they have failed to for some reason to sync for several days.

Your PC does need to be running, when it decides it ought to grab fresh
data from a time server - the default is once per day, but you can
adjust that to as frequent as 10minutes or so with a little utility.

Your PC runs tests to determine the network delays to the time server,
then works out how to offset to get an accurate time.

Your phone may need a setting to be made, to allow it it sync via the
cell network.

Between resyncs, they all rely upon a crystal controlled timebase to
keep the clock accurate, though some can be of quite poor accuracy.