Luke 7:45

ἧς is the genitive singular feminine form of the relative pronoun ὅς, ἥ, ὅ, meaning "whose, of whom, of which." It does not function as "when" or "time since." Typically, ἧς serves a possessive or partitive role in a sentence:

• Possessive Genitive: ἡ γυνὴ ἧς ὁ ἀνήρ σοφός ἐστιν → "The woman whose husband is wise."
• Objective Genitive: ἀκούω τῆς φωνῆς ἧς εἶπεν → "I hear the voice which he spoke."
• Partitive Genitive: ἕν τῶν βιβλίων, ἧς ἡ διδασκαλία χρησίμη ἐστίν → "One of the books, whose teaching is useful."

To express "when," Greek uses ὅτε (specific time) or ὁπότε (general/indefinite time), e.g., ὅτε ἦλθεν ("When he came") or ὁπότε ἦλθεν, ἠγάπησεν ἡμᾶς ("Whenever he came, he loved us.").

Every translation we've seen changes/adds this to "since the time" or "from the time."
The Berean Literal Bible italizes it as an addition:

"You did not give to Me a kiss, but from which time I came in, she herself has not ceased kissing My feet."

Berean Literal Bible