I'm still amazed that there is short English word for "a person that makes up crosswords" (cruciverbalist) and there is none for "the day after tomorrow".
@johny It's archaic. Nobody plans that far ahead any more. https://en.m.wiktionary.org/wiki/overmorrow
@johny I was just trying to come up with a joke reason it might have fallen out of use. I like the sound of the word Ubermorgen a lot better than Overmorrow, myself. Might have been as simple as a historical tonal preference for "the day after tomorrow"