You can tell a lot about the civilization by the holidays it celebrates. From this perspective, Nazi Germany was a highly eclectic civilization (to put it mildly).
Obviously, the Third Reich celebrated unique Nazi holidays that were used by its propaganda machine to instill in German citizens loyalty and obedience to the Nazi regime (and personally to Adolf Hitler), love and gratitude to “all of the above” and inspire Germans to make the maximum contribution to victory in the existential war.
Actually, Nazis tried (more or less successfully) use all holidays as tools for public indoctrination in the ideas of national-socialism. Thus, celebrations of major national holidays were supervised by Reich Propaganda Ministry, and were usually accompanied by mass meetings, parades, speeches and radio broadcasts.
Nazis celebrated Hitler’s appointment as Chancellor of Germany (January 30), the announcement of the Party program in 1920 (24 February), Hitler’s birthday (20 April) and the Memorial Day for the martyrs of the Nazi movement (9 November). As many Nazis (including Adolf Hitler) were Great War veterans, it is no surprise that they continued to celebrate Heroes’ Memorial Day (16 March or Sunday before 16 March).
Despite becoming the Nazi Germany, the country still remained heavily (and fundamentally) Christian. And Nazis have signed concordats with both Catholic and Protestant Churches. Consequently, they continued to celebrate Catholic holidays: Good Friday, Easter Sunday and Monday; Christmas; St. Stephen’s Day (next day after Christmas); Christ Ascension Day; Mothering Sunday; and the Pentecost Day.
Regions with predominantly Catholic population (Bavaria, Paderborn, etc.) celebrated the Corpus Christi holiday; regions with predominantly Protestant population celebrated Reformation Day and Day of Repentance and Prayer.
However, the Third Reich celebrated decidedly pagan holidays as well – Harvest Festival (Reich Harvest Thanksgiving Festival) – festival of German peasantry and farmers as well as Summer and Winter Solistices.
Nazi Germany was a national-socialist state so it is no surprise that the National Labour Day (1 May) was celebrated big time. And, of course, the long list of Nazi Holidays included the New Year.