Force NTP step whenever the Internet comes up

Assume there is a PC with dead CMOS battery and unreliable Internet connection. As far as I understand, both chrony and ntpd try to correct huge time differences (years) *once* – upon startup, – but then switch to slewing during normal system run, which will panic and bail out if the needed time correction is more than 1000 s. Sometimes the Internet connection is absent at boot time but comes up later; but my system is forever stuck in the past. Right now I solve this by manually calling chronyc burst 4/4 on OpenSuSE (chrony) or service ntp stop ntpd -gq service ntp start on antiX (ntpd). I wonder if there is some way to attach this to some hook that would fire once whenever the Internet comes up.