The working week in the emirates will be cut down to 36 hours from 48 hours, or 6 hours a day, UAE daily Gulf News reported, citing a Ministry statement.
The conditions apply to all workers, Muslim and non-Muslim, the report said, adding that employers cannot force workers to work the extra hours.
Companies flouting the work hours will face hefty penalties and workers are encouraged to report any violations to the Ministry of Labour.
However, special work shifts can be implemented as required, but employers need to inform employees in advance.
Employees can work overtime for a maximum of two hours and those who choose to do so have to be compensated accordingly.
"In case if an employee chooses to work overtime he has to be paid 25 per cent of his basic salary per day for day time and 50 per cent for night time duty," the report said.
Ramadan, the Islamic fasting month in which Muslims abstain from food, drink and other activities from dawn until dusk, is set to begin on July 20 or 21.