Public agencies will open at 10 a.m. Monday and all appointments made before that time will be cancelled, authorities said.
Hospitals will not be affected by the reduced schedule.
Also, banks warn that some branches may shut down and are advising customers to call ahead of a planned visit.
Buses serving northern and northwestern Athens suburbs will also not go to places where significant snow has accumulated and will shorten their routes. More than 40 lines are affected; 301, 324, 525, 723 and 861 will not operate.
There will be no passenger shipping services from the ports of Piraeus, Rafina and Lavrio Monday, as strong gales are blowing in many parts of the Aegean.
Ferries from northern ports to the islands of Samothraki and Thasos , as well as services to the Sporades islands and Evia, in central Greece, will also be shut down.
More snow is expected Monday in Attica, but also on many Aegean islands, including Crete.