When a official time changes what's happend in real time ?

Hello, When a TZ change in France in the middle of the night i sleep so i have never see if hour change in real time... I see on http://en.wikipedia.org/wiki/Network_Time_Protocol#Microsoft_Windows than W32TIME can have an 1-2 second error.. is http://www.meinberg.de/english/sw/ntp.htm is more precise ? Have a nice day/night ;)