What changes
Module 5F (MIB3): adaptation 0B12 = 00. The MMI clock no longer switches to summer time.
Details
Adaptation 0B12 (Summer_Time_Shift_Method in the MIB3 firmware adaptation table): 00 — no shift, 01 — manual, 02 — Europe, 03 — USA, 04 — automatic. Russia has no summer time, and with 'Europe' the MMI clock jumps an hour twice a year. 'Automatic' takes the time zone from navigation. MIB3 only (from model year 2021): the MIB2+ (MH2p, 2019–2020) has no such object, and Odyx refuses before writing. If module 5F is SFD-protected (Q3 F3 from model year 2021), Odyx asks for a token; some Chinese MIB3 units have no SFD — then no token is needed. 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.