All banks and shops and most museums and ancient sites close on public holidays.
Many ancient sites in Athens offer free entry on the first Sunday of the month, November to March.
National public holidays:
New Year's Day 1 January
Epiphany 6 January
First Monday in Lent February
Greek Independence Day 25 March
Orthodox Easter (Good Friday to Easter Monday) 26–29 April 2019, 17–20 April 2020, 30 April–3 May 2021, 22–25 April 2022
Labour Day (Protomagia) 1 May
Pentecost Monday (Agiou Pnevmatos) 50 days after Easter Sunday
Feast of the Assumption 15 August
Ohi Day 28 October
Christmas Day 25 December
St Stephen's Day 26 December