13 = M
5 = E
29 + 13= 42
Rev 13:5 It was given a mouth speaking great things and blasphemies, and it was given authority to act for 42 months.
11/9/2001 to 5/4/2005 = 42 Months
29/7/1980 to 13/5/1983 = 1018 Days
29/7/1980 to 13/2/1998 = 6408 Days