Dubai offices use the standard Gregorian calendar and Hijri Calendar for Islamic holidays. The Gregorian is a solar calendar with 365 or 366 days in a leap year, whereas the Hijri calendar is a lunar calendar with 354 days. Further facts about Islamic one has a lot to do with local sightings of the moon, which can vary by a day from the anticipated date. You must have got the annual calendar with holidays via e-mail or as a physical product. So, you can watch the rest of the details there.