Our ntp settings got screwed up (though it’s more accurate to say that I screwed up our ntp settings.) To determine what the current settings are:
$ ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+ns1.uchicago.ed darkcity.cerias 2 u 4 64 377 3.372 -2.833 1.466
*ns4.uchicago.ed tick.uh.edu 2 u 123 128 377 0.389 -4.102 0.163
+ns5.uchicago.ed tick.uh.edu 2 u - 64 377 0.459 -4.140 0.082
Note that if above it shows 0.0.0.0 as the refid, the system is NOT communicating with the ntp server.