MNA � Iran will officially turn clocks back by one hour at midnight (1930 GMT) on Saturday, September 21, readjusting to standard time after six months of practicing Daylight Saving Time (DST).

Hassan Khoshkhou, the caretaker of the Operations Department at Imam Khomeini airport, told IKAC press that all flights will be operated according to the time written on tickets and Passengers must arrive at the Imam Khomeini Airport City three hours before the ticket time.

In 2007, Iran�s Parliament passed a bill mandating the official time to be changed twice a year.

According to the bill, the country�s official time will be changed once at the beginning of the Iranian calendar year (on March 20 or March 21 on leap years) and once at the start of the second half of the Iranian year.

DST is the convention of advancing clocks by one hour so that evenings include more hours of daylight.

Typically, clocks are adjusted forward one hour in late winter or early spring and are moved one hour back in fall.