☾ When does the Moon change signs? Every two and a half days, and a room to notice each time

The Moon moves into a new zodiac sign about every two and a half days. Umbriel's free Moon Moved House catches each move at your local time and asks you to look around the room you are in: "The Moon just moved into Virgo." You type three words about the room. Over a year that is about 145 rooms, each under the sign the Moon was in, on a plate you can print.

• What you'll needThree words; no chart and no account
• What you getThe time the Moon entered its current sign and when it enters the next, in your own clock, three words about the room you are in, and a printable row of every room, each under the Moon's sign
• CostFree, no account required

The Moon is the fastest thing in the astrological sky, changing sign about a dozen times a month. Most people never notice. The Moon Moved House gives each move a small moment of noticing.

Each time the Moon enters a new sign, the card says so, at your local time: "The Moon just moved into Virgo. Look around the room you're in." You type three words about the room. The desk, the light, the noise, whatever is there. Fewer is fine; more is kept to the first three without a word of complaint.

It is forgiving about timing. The Moon's latest move stays open for as long as it is the latest, two days or more, and the move before it stays open for a further day after the Moon has moved on again. Nothing is ever refused for being late.

The card always shows when the Moon entered its current sign and when it enters the next, in your own clock, so it doubles as a plain answer to "what sign is the Moon in, and until when?"

Over a year the rooms line up, about 145 of them, in order, each under the sign the Moon was in, as an engraved plate you can print. A move with no room is blank paper: no hole, no zero, no streak. If you want, a silent nudge can appear when the Moon moves, while Umbriel is open.

Your rooms stay private, on your device, and if you sign in they sync end to end encrypted, the same way the journal does. Nothing is posted.

Every move is the engine's own ingress: the Moon's longitude is searched for each 30° boundary and the crossing bisected to the moment, and nothing about when or which sign is typed in. The times are good to a few minutes, because the Moon's longitude is measured against NASA's JPL ephemeris at a mean of 1.3 arcminutes and a worst of 5, and the Moon covers 5 arcminutes in about nine minutes. A room is matched to its move by the sign and the hour rather than to the exact millisecond, because two searches over different windows can bisect to instants a fraction of a second apart. The latest move stays open for as long as it is the latest, and the one before it for a further 24 hours. Up to three words are kept per room; a longer entry keeps its first three. The optional nudge is silent and only appears while Umbriel is open in a tab; nothing is sent to a server to make it happen.