The last time Pluto was in Aquarius was 1777.
That kind of question is answerable — it just isn't written down anywhere convenient. So here it is: every sign ingress of the five slow planets from 1700 to 2100, computed from an ephemeris.
Dates only. No "and that was the year X happened" — the events in that kind of pairing are picked, the picking isn't checkable, and it turns a table you can verify line by line into one more opinion.
Jupiter and Saturn last met in 2020. Before that, 2000.
A single planet's ingress is one kind of question. The other kind is what two slow planets are doing to each other — and those cycles run longer than anyone's memory. Every conjunction, square and opposition between the five slow planets, same range, same ephemeris.
Squares and oppositions are counted too — a cycle has four corners, not one. "Passes" is how many times the two planets crossed the same angle in one go, direct and retrograde: one event stretched over months, not several. Uranus and Neptune moved so alike in 1906–1910 that their opposition was exact eight times across four and a half years.
These are the sky’s dates, the same for everyone. Which of your houses they fall in is not — work out your chart, free.
Two things the table shows on its own
Pluto doesn't spend equal time in each sign. It runs through Scorpio in under thirteen years and takes nearly thirty-three through Taurus. That isn't astrology — it's an eccentric orbit, moving fastest near perihelion. Anyone who tells you "Pluto spends about twenty years per sign" is averaging away the most interesting part.
And the outer planets almost always cross a sign boundary more than once. They step in, retrograde back out, and step in again months later — sometimes twice over. The table marks every one of those, because "Pluto entered Aquarius in 2023" and "Pluto settled into Aquarius in 2024" are both true and people argue about which to use.
Dates are UTC, matching the convention of published ephemeris tables. Elsewhere on this site times are Beijing — that inconsistency is deliberate, so these dates can be checked against other sources without an off-by-one day.