in these files http://www.nbp.pl/homen.aspx?c=/ascx/ArchAen.ascx   Narodowy Bank Polski - Internet Information Service www.nbp.pl Average exchange rates table in: 2017. Average exchange rates table in: 2016. Average exchange rates table in: 2015. Average exchange rates table in: 2014. I see that are missing the rate during bank holiday (i.e in 2017 is missing Easter Monday and 06/01) Which rate will use this program for that missing date (for EUR->PLN conversion during pit38 declaration)?