+* introduce ntp.service (or suchlike) as symlink that is used to arbitrate between various
+ NTP implementations
+
+* timer units should get the ability to trigger when:
+ - CLOCK_REALTIME makes jumps (TFD_TIMER_CANCEL_ON_SET)
+ - DST changes
+
+* update the kernel's TZ (sys_tz) when DST changes
+
+* sync down the system time to the RTC when:
+ - CLOCK_REALTIME makes jumps (the user explicitely requested a time set)
+ - DST/timezone changes && ntp is active && RTC-in-localtime (never do it without ntp)
+ This takes care of syncing ntpdate updates to the RTC, and DST updates for localtime
+ mode, it will never touch the RTC if the no reliable time source is active or the
+ user did not request anything like it.
+