Where does “ημερονύκτιο” come from?

ημερονύκτιο (Greek) comes from Greek ημέρα, from Ancient Greek Ἡμέρα, from Ancient Greek ἦμαρ, from Proto-Hellenic ā́mər, from Proto-Indo-European h₂eh₃mr̥, from Proto-Indo-European h₂eh₃- — to be hot; to burn.

ημερονύκτιο (Greek): 24 hours, a day and a night

Definitions

24 hours, a day and a night

Ancestry of “ημερονύκτιο”, step by step

ημερονύκτιο traces back through two separate lines of ancestry.

via Greek ημέρα

Step	Language	Word	Meaning
1	Greek	ημέρα	day; hours of daylight
2	Ancient Greek	Ἡμέρα	—
3	Ancient Greek	ἦμαρ	day; by day; midday
4	Proto-Hellenic	ā́mər	day
5	Proto-Indo-European	h₂eh₃mr̥	heat
6	Proto-Indo-European	h₂eh₃-	to be hot; to burn

via Greek νύχτα

Step	Language	Word	Meaning
1	Greek	νύχτα	night
2	Ancient Greek	Νύξ	Nyx
3	Ancient Greek	νύξ	night
4	Proto-Indo-European	nókʷts	night
5	Proto-Indo-European	negʷ-	bare, naked

Every word from Proto-Indo-European h₂eh₃- →Every word from Proto-Indo-European h₂eh₃mr̥ →Every word from Proto-Hellenic ā́mər →