Where does “νυχθημερόν” come from?

νυχθημερόν (Greek) comes from Ancient Greek νυχθήμερον, 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.

νυχθημερόν (Greek): for a day and a night continuously

Definitions

for a day and a night continuously

Ancestry of “νυχθημερόν”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	νυχθήμερον	a day and night, the space of 24 hours
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

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