IIRC in Saudi Arabia the start and end of daylight savings is decided on each year, so not only do you need a historical record, but there's no way to future-pr

IIRC in Saudi Arabia the start and end of daylight savings is decided on each year, so not only do you need a historical record, but there's no way to future-proof it without integrating some external source of data, otherwise you'd need to manually add the dates for each year at some point.