A little help with time calculations

[iminal]

what i have so far is :

    # Get values needed to make time calculations
    CT = input("input your chronometer time (ex. 07:21:46): ")
    CE = input("input your chronometer correction (ex. 00:01:32): ")
    CEfastslow = raw_input("is your chronometer correction fast or
slow: ")

    #decide either to subtract or add CE from/to CT
    if CEfastslow == "fast":
        CEfastslow = CT - CE
    if CEfastslow == "slow":
        CEfastslow = CT + CE

but this just doesnt deal with the numbers in time format its acting
like they are just regualr integers adding them up like regular numbers

i am trying to figure out what u posted and it seems a little
complicated im trying to add it in somehow and figure out exactly what
its doing but still looking for a little easier of a way

thanks so far