I got this problem on my S6 (going on CET time, living in Sweden) as well. The problem corrected itself after a day or two. However, another, "cosmetic" bug persists. There's this thiny icon that appeared just on the right side of the clock, representing sun with a small clock inside - I assume an indicator regarding daylight savings thing. But it won't go away. I guess this was supposed to be there just the first day or two after the time changed, but it's still there - a week later. Removing / re-adding the weather widget wouldn't fix the problem. I also cleaned the cache from the widget - nothing.