The book, The Harbinger, best explains the seven year cycles. It is from Hebrew and Christian foundations. Also, every 50th year is the Year of Jubilee (Old Testament). On the 50th debts are forgiven and slaves are set free. 1947 was Jubilee, 1967 was Jubilee and 2017 is the next Year of Jubilee. If all the world currencies were collapsed and every government were in debt to its eyeballs - 2017 would be a year to forgive all the fiscal irresponsibility, wipe slates clean and introduce a new global currency.
That’s interesting but.........the math? 1947 to 1967 is only 20 years? According to what I’ve read, the last Christian Jubilee year was 2000 and the next is to be 2025.
...then you can throw the ‘blood moons’ into the mix...