Where does “calendis” come from?

calendis (Middle English) comes from Latin kalendas, from Latin calandus, from Latin calō, from Proto-Indo-European ḱelh₁- — to warm up, to be hot; to warm up, be hot.

Ancestry of “calendis”, step by step

Step	Language	Word	Meaning
1	Latin	kalendas	accusative plural of kalendae
2	Latin	calandus	which is to be called; which is to be announced...
3	Latin	calō	to call, announce solemnly, call out
4	Proto-Indo-European	ḱelh₁-	to warm up, to be hot; to warm up, be hot

Every word from Proto-Indo-European ḱelh₁- →Every word from Latin calō →Every word from Latin calandus →