SNTP over the Israeli servers only, nearest to Jerusalem first: the
National Physical Laboratory's ntp.ac.il, the atomic clocks of Israel
Standard Time, then the Hebrew University, then Tel Aviv, Petah Tikva,
Haifa, then the Israeli pool.  The first one that answers wins.  Four
questions each, the fastest round trip is believed.  Answers that are
not from a server, unsynchronized, a kiss of death, or from an address
we did not ask, are not believed.  Glowies.

The result goes to sys_clock_adj, RAM only, never the CMOS.  Once.HC
runs Ntp at boot after the network, NtpDaemon asks again every six
hours without a word on the screen.  NtpRep says who answered and how
far off the RTC was.

Tested in QEMU with the RTC set to 2020-01-01: at boot the Israeli pool
answered (stratum 2, following the Hebrew University), Now() matched
the host's UTC to the second, the bare RTC still read 2020, and
sys_clock_adj=0 put the Temple back in 2020 until Ntp ran again.