Kiniu

The energy of a light is getting bigger, when it comes clouser to the objects with a great mass, thatswhy the time goes sllower. My question is what influance does have the gravity of our Universe (the milky way) on the light from outher galaxys and is it possible, that we measure the speed(in years) of expansion of the universe with a failure assuming that velocity of a light is the same between the galaxys and nearby them?