Yesterday, I forgot to invoice Yahoo for the last month’s worth of stories, and my stupid oversight may save me a little money next year.

That’s because the odds of payment for November’s work at Yahoo Finance arriving by Dec. 31 just got two days’ worse. And if I don’t get paid by then, I don’t owe taxes on the money until 2017.

The downside of this scenario is that my 2016 income, already assured to fall below 2015’s because I wrote less than usual in early summer, will drop even more. That potential embarrassment bugs me, but apparently not enough that I remembered to get the payment machinery in gear by Friday.

Deferring income isn’t exactly an advanced financial hack, but it is something I couldn’t do when I worked on a salary.

Tax calculations should also drive me to go on a moderate hardware-spending binge this month. My laptop and my desktop are both ancient, and replacing either now would put a nice big expense on my Schedule C.

Alas, Apple seems uninterested in shipping a new laptop in my price range, or a new desktop at any price. The Windows universe offers a few enticing options, but on closer inspection I realize that the laptops I like all omit at least one feature I’d appreciate.

More important, CES is now only a month away. And I can’t possibly make any big electronics purchases before using that event to see what the gadget industry has in store for this year–its no accident that electronics rarely land on my Christmas list.

That leaves me another way to lower my tax burden: a late-December spree of charitable donations. You may have read a lot on Twitter about #GivingTuesday this week, but for me that day comes on the last Tuesday of this month–when I know the donation will count for my 2016 taxes but won’t come due on on my credit-card bill until sometime in February. Please do the same if you’re financially able.