The word(s) "well-known" appears 4 time(s) in 4 verse(s) in Quran in Saheeh International translation.

(1) Hajj is [during] well-known months, so whoever has made Hajj obligatory upon himself therein [by entering the state of ihram], there is [to be for him] no sexual relations and no disobedience and no disputing during Hajj. And whatever good you do - Allah knows it. And take provisions, but indeed, the best provision is fear of Allah. And fear Me, O you of understanding.

(2) Until the Day of the time well-known."

(3) So the magicians were assembled for the appointment of a well-known day.

(4) Until the Day of the time well-known."