Day Date Month Holiday
Friday 06 Jan Epiphany
Monday 27 Feb Ash Monday
Friday 14 Apr Good Friday (Orthodox/Katholic)
Monday 17 Apr Easter Monday (Orthodox/Katholic)
Monday 01 May Labour Day Holiday
Monday 05 Jun Whit Monday
Tuesday 15 Aug Assumption Day
Monday 25 Dec Christmas
Tuesday 26 Dec Second Day of Christmas
Source: http://www.helex.gr/web/guest/market-securities-holidays