If we take powers of 2 in groups of 3 we get 2^0=1, 2^1=2, 2^2=4; then 2^3=8, 2^4=16, 2^5=32. The remainder after dividing by 7 is 1, 2, 4 for consecutive powers of 2 indefinitely. If the power of 2 is divisible by 3, the remainder is always 1 after dividing by 7. The reason for this is that 2^3=8 which is 7rem1. The power of 60 is divisible by 3 so 2^60/7 has a remainder of 1, therefore adding 2^60 is the same as adding 1. Add 1 day to Monday and we get Tuesday.