Interesting to me anyway:
There are 12 months in a year and 12 notes in the chromatic scale. Moreover, there are 7 long and 5 short months and there are 7 white and 5 black keys in each octave on the piano keyboard. The patterns of long/short months and white/black keys match as well:
- January (long) — F (white)
- February (short) — F# (black)
- March (long) — G (white)
- April (short) — G# (black)
- May (long) — A (white)
- June (short) — A# (black)
- July (long) — B (white)
- August (long) — C (white)
- September (short) — C# (black)
- October (long) — D (white)
- November (short) — D# (black)
- December (long) — E (white)