IDIOMS

eleventh hour

(idiomatic, usually hyphenated) Used attributively.

Example: 1857, William Makepeace Thackeray, The Virginians, ch. 85:
  If she repented, though at the eleventh hour, it was not too late.
1922, James Joyce, Ulysses, Episode 16
  Highly providential was the appearance on the scene of Corny Kelleher when Stephen was blissfully unconscious but for that man in the gap turning up at the eleventh hour the finis might have been that he might have been a candidate for the accident ward...
1961, Philip Toynbee, Underdogs: Eighteen Victims of Society‎‎, page 56:
  I have extricated myself so far at many eleventh hours and perhaps there is some hope in this.
2009, Tony Karon, "Why Money Alone Will Not Fix Gaza," Time, 3 March:
  Egypt had managed to bring the two sides to the brink of a deal two weeks ago, before internal political dynamics prompted the Israelis to back out at the eleventh hour.
2008, Bryan Walsh, "George W. Bush's Last Environmental Stand," Time, 5 Nov.:
  Eleventh-hour executive changes are not unique to this outgoing Administration — President Bill Clinton launched a number himself before leaving office.