Reading through the Psalms

I've been desiring to read in the psalms with some regularity, but I keep skipping days, and forgetting where I was (most days, I do it during a break at work using my phone). So, here's my new system for "remembering" what to read:

1. Take the day of the month.
2. Add to it according to the month you're in times 30, with January being 0, February being 1, March being 2, April being 3, May being four, June being 0 again, July being 1, etc.
3. November and December I may read Proverbs instead, or start over with 0 and 1 again.

This way, I can figure out what to read today, and don't have to remember, write down, etc.

So today, I was reading Psalm 81.