setting recurring task

[janrif]

What's the best way to set this up? I get confused by the begin time, end time, etc.

Example:

Buy dog food (usually lasts a month)
Remind myself to replenish in 30 days

I'd like to be able to set up a task (I have a form for this) and just hit a recurring 30 days or month if I could. Be able to find this in upcoming tasks for the month, etc. instead of recreating a task every month. But somehow I can't seem to make this recurring task work. It has something to do with the way I use the date/time attributes.

Thank you