The autumn equinox falls around the 22nd, and from that point the nights are longer than the days. Britain loses daylight faster in September than in any other month except March gains it — roughly four minutes an evening, which adds up to two hours over the course of September 2028.
All 30 days of September 2028 are ordinary working days outside the weekends, with nothing subtracted anywhere in the United Kingdom. Together with October it forms the longest continuous run of full working weeks in the British year.
September 2028 closes with the autumn term settled and the evenings drawing in hard. October follows with the clocks going back, half term in the last week or two, the paper tax return deadline and Halloween all inside the same month.