Until 1968, Saudi Arabia used
Arabic time, where clocks were set to 12 o'clock at sunset or when the
call to prayer for the
sunset prayer was heard. This was because the
Islamic calendar defines sunset as marking the beginning of a new day. However this later conflicted with the introduction of western sun time, which defined, in congruence with Europe, the start of a new day to be midnight. With western sun time, clocks were set to six o'clock at sun set. While western sun time was intended to be approximately equal to GMT+3, it being reliant on sunset time, which changed with the seasons, meant that large disparity could emerge between western sunset time and GMT+3 as seasons progressed. In addition to this, the American
Military Assistance Advisory Group introduced "
Zulu time".
Saudia used GMT+3 for most of the country, except for
Dhahran which was set at GMT+4. The
American Arabian Oil Company, used to also observe daylight savings for its headquarters in Dhahran. Similarly, the
Trans-Arabian Pipeline Company also observed daylight savings for its pumps in the east of the country. ==tz database==