SNMP Graph

Maybe a simple question for the experts .....

I want to collect SNMP-data using SNMP Graph for a fixed period of time each day. It would be very comfortable to have a scheduler or something like that.
Up to now I have not found anything helpful. (Maybe I'am stupid..:-()
What can I do to automate/schedule tasks like this ?

Thanks for your help in advance!

Regards
Ralf