The circular was issued as per Cabinet Decision No 13 of 2012 in implementation of Federal Law No 11 of 2008 and its amendments.
The holy month of fasting is expected to begin on June 6, subject to moon sighting.
School hours will also be shortened across the country as Ramadan overlaps with the last days of the academic calendar.
Thousands of school pupils will be sitting critical examinations, such as the ACT or A Levels, during Ramadan this year.
Private sector working hours are yet to be announced.
Companies are not required to follow the same timings but are expected to reduce working hours for employees.
Source: The National