Not sure if this is a bug or not, but the behavior seems odd to me.
Sometime recently, I think the mobile app was updated to automatically roll over when a new month hits. I'm not sure of the details of how this happens, but today is 12/1, and my app has all the new amounts. Two days ago, I synced. Yesterday (11/30), I entered a transaction but dated it for 12/1 because I wanted it to come out of next month's budget. Today, my phone says: $440 Budget, -$12.67 Spent; $440 Remaining. Seems to me there's a math error here ;-) If there is logic to this behavior, please explain it to me!