Where does “počasí” come from?

počasí (Czech) comes from Old Czech počěsie, from Old Czech čas, from Proto-Slavic časъ, from Proto-Balto-Slavic keʔs-, from Proto-Indo-European k(ʷ)eh₁s-.

počasí (Czech): weather

Definitions

weather

Ancestry of “počasí”, step by step

Step	Language	Word	Meaning
1	Old Czech	počěsie	opportunity
2	Old Czech	čas	time
3	Proto-Slavic	časъ	time
4	Proto-Balto-Slavic	keʔs-	—
5	Proto-Indo-European	k(ʷ)eh₁s-	—

Every word from Proto-Indo-European k(ʷ)eh₁s- →Every word from Proto-Balto-Slavic keʔs- →Every word from Proto-Slavic časъ →