(colloquial, rhetorical question, sarcastic) From what time.
Since when do I need your permission?
(colloquial, rhetorical question, sarcastic) (as an interrogative interjection) Used to indicate doubt as to the veracity of a statement.
The moon is made of green cheese. Since when?
Since-when Sentence Examples
Anyway, since when did you get to be such a mother hen?
Diphtheria first appeared in 1868 and continued as a severe epidemic until 1872, since when it has only occurred at rare intervals and in isolated cases.
Lewes points out that Leibnitz is inconsistent in his account of the intelligence of man in relation to that of lower animals, since when answering Locke he no longer regards these as differing in degree only.
She was married in childhood to Lionel, son of Edward III., who was recognized in her right as earl of Ulster, and their direct representative, the duke of York, ascended the throne in 1461 as Edward IV., since when the earldom of Ulster has been only held by members of the royal family.
The tea plant was first introduced in Natal in 1850, but little attention was paid to it until the failure of the coffee plantations about 1875, since when only small quantities of coffee have been produced.