Track · 2:30 · Liner note

September Meets Last September

Name: September Meets Last September
Duration: 2 min 30 s
Description: Comparing a period with the same period a year earlier removes seasonality from the comparison, though calendar differences such as weekday mix and moved holidays still need adjusting for.

Comparing a period with the same period a year earlier removes seasonality from the comparison, though calendar differences such as weekday mix and moved holidays still need adjusting for.

September looks strong until you compare it with August, because August is always quiet. The fair comparison is last September. September Meets Last September is the seasonality-aware view: same period, one year apart, so the calendar’s regular pattern cancels out.

Mind the small differences. A month with five weekends, a holiday that moved or a leap day can tilt the ratio. Align by weekday, show the absolute values beside the percentage and note any change in how the metric is counted.