See again
http://www.kinook.com/Forum/showthre...?threadid=2347
"reminder triggers on/at:
(begin date/time) - (reminder value)
To see when the reminder will be triggered, see "pending reminder" attribute"
Set the start date (start time really not that relevant). Set recurring attribute to "monthly". Set end date if you know when your dog is going to be dead

Set reminder maybe to 2,3 days, so that you get reminded 2,3 days before you'll be out of dog food. But as you just approximating that your dog food is going to last a month, the reminder can be set just to zero, cause it makes no difference really.