Backend frontend difference is normal, as Backend times are UTC times (no timezone and daylight saving applied on that)
The difference (1 or 2 hours) can be in user config. If a user have GMT+1 with Daylight Savings on, he or she will have +2 hours, another user with GMT+0 with Summert time on have only 1 hour difference. The only problem is +1 hour addition in case of saving event. I’ll check and fix it really soon.