Apart from the countries listed below, Epiphany is a public holiday in Poland and in some regions of Germany, too, but there is no truck ban in force on this day.
Also, please bear in mind that there is a truck ban in Croatia on Wednesday, 5th January, when HGVs are not allowed to travel from 3pm to 11pm.
These are the countries where truck bans are in force on 6th January:
Austria: from midnight to 10pm.
Croatia: from 2pm to 11pm.
Slovakia: from midnight to 10pm. However, a general exemption from the driving ban has been introduced: it applies to all heavy goods vehicles traveling on motorways, roads for motor vehicles, class I roads and roads with international traffic, entering Slovakia from some neighbouring countries and bound for destinations (e.g. company headquarters or unloading place) located within Slovakia.
Italy: from 9am to 10pm.