The story
From year + -tide (“time, occasion”). Compare West Frisian jiertiid (“season”), Dutch jaartijd, jaargetijde (“season”), German Jahreszeit (“season”), Swedish årstid (“season”), Icelandic árstíð (“season”), Yiddish יאָרצײַט (yortsayt). Piecewise doublet of yahrzeit.
Etymology from Wiktionary, CC BY-SA 4.0.