That information won’t be lost, though. It just would be expressed differently. They are no longer in a +8 hour time zone, which given your own location in a +1 hour zone would lead to a most likely open time of 8 - 8 + 1 = 1 til 17 - 8 + 1 = 10 your time, but in an area where opening hours are most likely between 0100 and 1000.
There is still a lookup, but no longer a lookup of time difference of the area, but a lookup of usual business hours in the area.