Palmesøndag (Palm Sunday) is by definition actually the last Sunday before Easter so it can be calculated by subtracting 7 from the date for the Easter Sunday (Påskedag)
Påskedag (Easter) is the first Sunday after the first full moom after March 21th
Pinse (Sunday of the feast of Pentecost) is the 7th Sunday after Easter
The current version of the Danish holidays definition does not include three holidays. Below are the details from https://github.com/sql-bi/Bravo/issues/793#issuecomment-2241780291