If you are working in Saudi Arabia, then for all official and legal activities in Saudi Arabia, the Hejri / Arabic calender is followed. From stamping of your passport to receiving your salaries in government sector and many private companies follow the the Hejri calender.
Most importantly, the iqama renewal, visa expiry etc are all calculated using the Hejri calender.
The Hejri calender is based on the cycles of the moon and is shorter by approximately 11 days compared to the Gregorian / International calender.
You can convert convert the dates to Hijri or Gregorian using the below program –
(note: The result will be displayed on external website)