Green’s Dictionary of Slang

a catchphrase used in answer to the query, ‘What time is it?’.

1738		Swift Polite Conversation 23: nev.: Pray Miss, what’s o’ Clock? [...] lady answ.: Why, ’tis half an Hour past Hanging Time.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1907		J.W. Carr ‘Word-List from Hampstead, N.H.’ in DN III iii 189: half past kissing time, time to kiss again, phr. Facetious answer to the question: ‘What time is it?’.
1910		B.L. Bowen ‘Word-List From Western New York’ in DN III:vi 442: half past kissing time, n. phr. Facetious reply to the question ‘What time is it?’ sometimes the expression time to kiss again is added.
1922		Joyce Ulysses 345: And when Cissy came up Edy asked her the time and Miss Cissy, as glib as you like, said it was half past kissing time, time to kiss again.
1939		J. Campbell Babe is Wise 216: So c’m on now [...] or we won’t be in town till half pas’ kissing-time.