I've encountered an issue when using a system that has both connman and the
hwclock.sh script enabled during startup. The default combined startup
order for these two services is wrong.

Currently connman starts at 05, and hwclock.sh is at 20 (default for
update-rc.d). This means that we have a situation where connman starts up
and obtains a correct NTP time, then hwclock.sh clobbers the system time
with whatever is in the RTC even if it is way in the past. The big issue
caused by that is connman schedules its next NTP update at an absolute time
of (current time + 1024s). Once the hwclock.sh script knocks the system
time way into the past, the NTP update will not run for a potentially very
long time.

I would suggest adding a line to poky/meta/recipes-core/busybox.inc to move
hwclock.sh earlier.
For example:
INITSCRIPT_PARAMS:${PN}-hwclock = "start 04 2 3 4 5 . stop 20 0 1 6"
or
INITSCRIPT_PARAMS:${PN}-hwclock = "start 40 S . stop 20 0 1 6"

Thanks,
Chris Elledge