answered
2016-04-14 08:49:53 +0200
When automatic time update is selected in a phone, it should use both ntp and nitz for time synchronization.
On slow data connections (2g etc) the ntp queries made by connman might timeout and fail. The time queries are repeated periodically (every 15 minutes or so IIRC). Toggling the setting off + on again should restart the ntp polling sequence and might allow getting system time in sync faster.
Whether and what kind of NITZ data is sent varies from one network to another. In some cases it might be that while phone is using 3g connections nitz data is received but not in 4g connection. Forcing 3g temporarily (and possibly rebooting / switching to airplane mode and back) might help.
Did you also try this while connected to WLAN?
lakutalo ( 2016-04-13 21:01:44 +0200 )edit