They get 7 times from Daniel 4:16
Maybe the "time, times and half a time" language "explains" the gap between 1914 and 1919 (when the the Bible Students were supposedly chosen by God). Like I said, it's been a while. I distinctly remembe studying the Revelation Grand Climax book and being unsatisfied by the explanation.
Edit: Not trying to hijack, but I found this in a copy of the old Revelation book:
How long did this respite for the seed of God’s woman last? Revelation 12:6 says 1,260 days. Revelation 12:14 calls the period a time, times, and half a time; in other words, three and a half times. In fact, both expressions stand for three and a half years, extending in the Northern Hemisphere from the spring of 1919 to the autumn of 1922. This was a period of refreshing recuperation and reorganization for the restored John class.
Three giant leaps of logic here: (1) Times means exactly two times (2) three and a half times means three and a half years (3) This prophesied a random period of time between 1919 and 1922, a period of "refreshing recuperation and reorganization."