Firstly, the 1260 is clearly in the Bible as days — have you ever read the bible?
Is the 70 weeks of Daniel 70 weeks or 490 years?
The answer is 490 years. Same principle.
1260 years of Catholic rule and persecution:
538-1798 and that is ALSO historically documented.
Daniel’s is Daniels and John’s Apocalypse is John’s Apocalypse.
You do realize those are two different books, right? Just because they’re in one pamphlet by your Adventist prophetess Ellen G White, doesn’t make them written by the same person — or do you believe that Ellen G White wrote them?