Where does “трёхдневный” come from?

трёхдневный (Russian) comes from Russian день, from Old East Slavic дьнь, from Proto-Slavic dь̑nь — day.

трёхдневный (Russian): three-day

Definitions

  1. three-day

Ancestry of “трёхдневный”, step by step

StepLanguageWordMeaning
1Russianденьday, daytime; afternoon, early evening;...
2Old East Slavicдьньday
3Proto-Slavicdь̑nьday
Every word from Proto-Slavic dь̑nьEvery word from Old East Slavic дьньEvery word from Russian день