Calendar insights
What the A and B groups mean
Fourteen labels organize dates without giving them mystical significance.
Seven places in a repeating cycle
There are seven possible weekday positions in any continuous sequence. Always Happens labels the January–February cycle A1 through A7, beginning with January 1. It labels a separate cycle B1 through B7, beginning with March 1.
A label is not a weekday name
B2 does not permanently mean Monday, Tuesday or any other named weekday. The actual weekday changes with the year. The label records a relationship among dates, not a fixed weekday for all time. June 29 and August 24 are both B2 because they occupy the same position in the March–December seven-day cycle.
Why two cycles?
Separating the year around February preserves the distinction created by leap day. A1 and B1 are not merged even though their numbers match. A match inside one cycle can be permanent; a match between cycles requires a year-specific check.
Use the explanation, not just the code
A recipient should not need to memorize group labels to appreciate a discovery. The useful message is that their birthday and another date share a weekday every year under the stated conditions. Group codes belong in the supporting explanation where a curious reader can inspect the method. The labels make the system easier to test, but the human explanation should remain understandable without them.
Always Happens editorial draft · calendar claims are covered by automated tests; human editorial review is required before public launch.