> A lookup table for what? Probably just about anything you want, as is already commonly available. Mostly, I expect nations would have official business hour

> A lookup table for what? Probably just about anything you want, as is already commonly available. Mostly, I expect nations would have official business hours for public employees which would be easily searchable if you needed to call someone on another side of the world, which is not any more difficult than looking up what time zone they live in is now.