problem with time on 5x

Already 10 days in vacation in Montenegro and here is 1 hour less - the difference in time between here and my place. So, while my 5x connected to phone(IPhone 6S) the time is OK. But just my 5x is loosing connection with phone the times goes 1 hour less than local time. Tried to resolve it by synchronizing with GPS without success. When 5x is connecting to phone again the time getting correct but all my workouts, sleeps and so on are getting wrong time data. Maybe anybody can help with this? It is stupid to set up time on watch manually.