Year and month

Jason A. Donenfeld <Jason@zx2c4.com>

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2018 0 0 0 1 1 0 0 0 0 0 0 0
2020 0 0 0 1 0 0 0 0 0 0 0 1
2023 0 0 1 2 3 0 0 0 0 1 0 0