Shell Programming and Scripting

I am writting a script in the ksh shell and am trying to find a way to report the total execution time of the script without requiring the user to specify the time function when executing the script.
Does anyone have any examples they have used. I have been setting up two date variables (one at the beginning $START_TIME and one at the end $END_TIME) and then do some calulation of the difference and display is to the user in minutes. No matter what I do it keeps giving me syntax errors.
any help

I use this in our build script.

Code:

        start_time=$(date +%s)
.
.
.
        finish_time=$(date +%s)
        echo "Time duration: $((finish_time - start_time)) secs."

Divide the above by 60 to get minutes.

Something like

min=$(( $((finish_time - start_time)) /60 ))

date %s is a GNU extension so may not be available. You could use the ksh built-in variable $SECONDS instead.

Thanks Ygor for pointing that out.

Hmm... I should modify the script !

hye dude the syntax for setting start_date is not working...
i am workin in bash...
i too tried out printing the time taken by a process

What error are you encountering ?

Possibly you dont have GNU date. Post the results of

Code:

strings `which date` | grep '%s'

You should heed Ygor's suggestion.

$ strings `which date` | grep '%s'
$
Returns nothing
$ which date
/usr/bin/date
$

Here is the code I have been testing with:
#!/bin/ksh
start=$(date +%s)
time sleep 20
end=$(date +%s)
echo "Time: $((end - start)) secs."

Results: syntax error

changed to:
#!/bin/ksh
start=$SECONDS
time sleep 20
end=$SECONDS
echo "Time: $((end - start)) secs."

Results: This works!

My question now is, will it still work after hours of execution. How ofter does this value get reset?