I hear it's Feb 15, 2008:
Watchtower - February 15 2008 - page 24 paragraph 15:
15 Today, people who don't have the spiritual understanding think that there is nothing of "stunningly observable" as to the signs of Jesus' presence. They reason that all continues as before. (2 Peter 3:4) On the other hand, the faithful brothers of Christ, the present class of John, recognize this sign as if it was a lightning and understand its real meaning. As a group, those anointed comprise the present "generation" of comtemporaries who won't pass away "until all the things come to pass".* This indicates that some of anointed brothers of Christ will still be alive on earth when the foretold great tribulation begins.
footnote:
* Apparently, the period in which "this generation" lives seems to correspond to the period covered by the first vision of the book of Revelation. (Rev. 1:10-3:22) This aspect of the day of the Lord extends from 1914 until when the last of the faithful anointed dies and is ressurected - See Revelation - Its Grand Climax at Hand! page 24, paragraph 4.