Seriously, it's all about the percentages, not the calendar. You just split whatever hits your account each time. Timing barely matters once you track the categories.
My friend who works freelance uses a system where she sets aside money from each check for different bills. It doesn't matter if the amounts change, because she adjusts the percentages based on what comes in. So even with uneven pay, you can still split your income into needs, wants, and savings. She has a base budget for rent and groceries, and anything extra goes to debt or fun money. That way, the timing of the checks isn't as important as how you split the money. Honestly, it took me a while to get it, but now I see it works for any pay schedule.