Changing Cell Format

hi..i have a cell which has a time format.

but currently its displaying 2.00907E+13.

is it possible that i can convert it into the normal time format?

for example B2 in my sample is 20090718170156 which actually means 2009/07/18 17hrs 01min(s) 56Sec(s)

and after converting, how can i get the time difference between start time and end time?

P.S i tried doing a manuel format cells, but it didn't seem to work.