The default update interval in Munin is 5 minutes which is OK for most purposes.
For some cases though 5 minutes is too frequent, useless and sometimes increases load of the servers being watched. For example, I want to graph database sizes once every day and I have plugins written for that. But sampling every 5 minutes could be costly in terms of performance.
So, is it possible to configure Munin for specific graphs to update every day or every hour instead of every 5 minutes?