Use CTOT() then subtract. It will give you number of seconds. Rather than using TIME(), it may be easier to use DATETIME().

t1=DATETIME()
t2=DATETIME()

* Process

? t2-t1 && Number of seconds.

>What's the best way to calculate the interval?
>E.g.
>t1=Time()
>...as time goes by.....
>t2 = Time()
>
>?t2-t1 && of course does not work because t1, t2 are strings
>
>Is there a way of computing "t2-t2" without resorting to low level code?
>(I don't have Hacker's with me today)
>
>Thanks,
>Pete