Below is the chart explaining how the 70-week prophecy of Daniel 9:24-27 ties in with and forms the starting point of the 2,300-year prophecy of Daniel 8:14. If you count 2,300 years from 457 B.C. (remembering to delete the nonexistent zero year), you get 1844; or, if you count the remaining 1,810 years from A.D. 34 (2,300 minus the first 490 years), you come to 1844, as well. Thus, the cleansing of the sanctuary in Daniel 8:14 can be shown to start in 1844.
Notice, too, how the 1844 date fits with what we saw in Daniel chapters 7 and 8. That is, the judgment in Daniel chapter 7, which is the same thing as the cleansing of the sanctuary in Daniel chapter 8 (see the last two weeks’ lessons), occurs after the 1,260-years of persecution (Dan. 7:25) and yet before the Second Coming of Jesus and the establishment of His eternal kingdom.