What changes
Unit 5F, adaptation 0B12 = 04. The MMI determines time zone and daylight saving from navigation.
Details
Multimedia adaptation 0B12: daylight saving method — 00 none, 01 manual, 02 Europe, 03 USA, 04 automatic. On MIB3 the object is confirmed by the firmware, on MIB2 by a single source so far; if the unit does not know it, a3c refuses before writing. Russia has no daylight saving, and with the factory 'Europe' setting the MMI clock is off by an hour twice a year. 'Automatic' takes the time zone from navigation. If the unit is SFD-protected, a3c warns before writing. To restore the previous value, roll back from the history.
Other options
This is one option of the “Daylight saving time” setting: only one can be active.