Legally, Christmas Day is clearer than Christmas Eve. 25 December is a statutory public holiday under § 7 of the Working Rest Act. For most employees, that means holiday rest. [1]
Work on Christmas Day is not impossible, however. Hospitals, care, transport, safety, hotels, hospitality, tourism, energy supply and other permitted sectors may have rosters. That is why simply saying "free" is not enough; roster, collective agreement and sector remain important.