I wouldn't worry so much about percentages that people decide are appropriate -- just track your spending for a month or two and find out what you
really spend because I promise you that what's in your head is rarely what's really happening
Once you've tracked your spending you'll have an idea of what types of categories are appropriate and which don't apply to you.
To your specific question: I would worry about what you need to do
today so if that means that you're playing catch up then I would definitely build that into the budget. A budget is not a pie-in-the-sky plan of the perfect month. It's a system of sitting down at the beginning of a month and, to the best of your ability, anticipating and allocating your money to the places it needs to be.