Hi Anne, it's hard to say what would work best for you since everyone's finances and business situations are going to be different. I will say that when I look at our budget I look at the month so I can include regularly billed expenses, etc. in my planning.
I also have a quarterly overview because I need to budget for quarterly federal tax payments, yearly state tax payments [business and personal], as well as personal bills like car insurance and similar that are billed less frequently.
With all of that in mind, I found that it works best for me to invoice my clients every two weeks with Net 14 terms.
I'm not entirely clear on your question, so if I've missed the mark just post back!