Difference between two times using MS Excel

Before using any formula format the two cells in time format.And just subtract 2nd cell from 1st .

like

=A2-A3

Thanks for your reply.Actually I haven't been able to format the cells in time format.Please explain step wise to do the same

Dear

you can format the cell in time format or if you want you can do this without formation.

just write. 

in cell A1 and in cell A2 (assuming clock of 24hours)

14:40 (means its 2:40 pm)

2:30 (means its 2:30 am)

now write

=A2-A1 or vice versa.

:) hope now this is clear.

Select the cells and press CTRl+1 (not from numeric keypad) and u will be prompted to select format cells