Deficit on Income And Expenses Statement
My monthly expenses are about $1200. My income is low and irregular. One month it may be $1700 and I run surplus (I save $500), another month it may be only $800 and I run deficit (I spend $400 of my savings).
Should I include my savings from previous months (as well as savings on the day of bankruptcy) as income on each Income And Expenses Statement, so there is never a deficit ?

This is something that you should discuss with your trustee.
In our practice (which is based in Ontario) we instruct our clients to record all of their income and expenses on a CASH BASIS. That means you record income in the month that you receive it and expenses in the month that you pay them. If you are able to save money that’s great.