September is a month of two halves hinged on a single day. For the first ten days the Sun works through Virgo and the sky stays orderly; then the tenth arrives and three things happen almost at once. Mercury changes sign, Venus changes sign, and Uranus turns back on itself. Everything after that runs on noticeably different terms, and the second half of the month has little in common with the first.

Venus is the one to watch. She leaves Libra, where she has been comfortable and unhurried, for Scorpio, where nothing stays polite for long. The register shifts from fairness to appetite, from arrangement to attachment. Whatever felt civilised and manageable in early September will be asking something considerably more honest of you by the end of it.

Mercury moves the opposite way, out of Virgo and into Libra, trading precision for diplomacy — then slips into Scorpio right at the month's close, which is fair warning that October will ask a harder set of questions than September ever did.

Uranus reversing in Gemini on the same day reopens something you had considered finished: an idea abandoned, a course not completed, a conversation left mid-sentence. It will not conclude this month, or the next one, and pushing at it now achieves nothing at all.

The Moon marks the month at both ends. A New Moon in Virgo begins something quiet and practical mid-month, unglamorous enough to be underestimated. A Full Moon in Aries closes it far more loudly, and the Sun opposes Neptune on the same day, so what looks obvious then may not survive the following morning.

Mars spends September in Cancer, guarding rather than advancing, squaring Saturn on the very first day and setting an awkward tone that takes a fortnight to shake. It reaches Leo at the very end and joins Jupiter there, and the month closes with considerably more appetite than it opened with. Saturn and Neptune go on reversing through Aries beneath all of it, settling nothing whatsoever, exactly as they have since the summer and will until December.