Run a script with scheduled tasks

[tonkpils]

hi, i have made a search on this subject and i always find the cron to be the solution for me. But i am asking because i think what i want can be done differently.

here is the scenario:
i have a command line to grab stream and save it.
i want this command to be run at different time (hours) on specific days.
i should use the "at", as far as i saw here on the forum. But are there other way to do it?

can i have a simple script that i run the day of the event, before this occur?

thanks for your hints!

[tonkpils]

will try to be more clear:

this is what i run to grab the stream.
I have one for each stream source:
i run each of them in a separate terminal windows.

rtmpdump -r rtmp://10.11.12.123/website/stream.flv -o filename.flv

rtmpdump -r rtmp://10.11.12.123/website/stream1.flv -o filename1.flv

rtmpdump -r rtmp://10.11.12.123/website/stream2.flv -o filename2.flv

Now i should be able to run this commands when i am not at home, and schedule a task to run it at a given time.

how?