Where does “グレゴリオ暦” come from?

グレゴリオ暦 (Japanese) comes from Japanese グレゴリオ, from Italian Gregorio, from Latin Grēgorius, from Ancient Greek Γρηγόριος, from Ancient Greek -ῐος, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

グレゴリオ暦 (Japanese): The Gregorian calendar

Definitions

The Gregorian calendar

Ancestry of “グレゴリオ暦”, step by step

グレゴリオ暦 traces back through two separate lines of ancestry.

via Japanese グレゴリオ

Step	Language	Word	Meaning
1	Japanese	グレゴリオ	Gregorio
2	Italian	Gregorio	Gregory
3	Latin	Grēgorius	—
4	Ancient Greek	Γρηγόριος	watchful, vigilant
5	Ancient Greek	-ῐος	belonging to; of”, “belonging to”, “pertaining to
6	Proto-Indo-European	-yós	Creates adjectives from noun or verb stems

via Japanese 暦

Step	Language	Word	Meaning
1	Japanese	暦	a calendar; an almanac
2	Japanese	日	Sunday
3	Old Japanese	日	the sun; sunlight, sunshine; daytime, daylight
4	Proto-Japonic	*pi	day, sun

Every word from Proto-Indo-European -yós →Every word from Ancient Greek -ῐος →Every word from Ancient Greek Γρηγόριος →