"Until a time and times and the dividing of time" (Dan. 7.25); "a time, times and half a time" (12.7); "a time, and times, and half a time" (Rev. 12.14) where "they will trample the holy city for forty-two months" (11.2), "exercise authority for forty-two months" (13.5) "for 1,260 days" (11.3) which is "a thousand two hundred and threescore days" (12.6), "for a time, and times, and half a time" (12.14). From the time of the declaration to rebuild the temple was exactly 69 sevens (units of seven), each year in each seven 360 days, takes you right to the day Jesus entered Jerusalem, then 4 days later He was killed. So that is how we know given the other data that the first rapture according to readiness and resurrection begin on Sept. 14, 2015 applying the biblical year of 360 days. Incidentally 30 x 7 years is exactly 2,520 days, the smallest number divisible by all numbers 1 to 10. There is also mention of the 1290 days and 1335 days. 1290 is 30 more days Jesus will use for judgment upon the nations. 45 more days to the 1335th day is the time it will take to set up Israel as the center of all nations.