◌ What to do during a void-of-course Moon: nothing, for two minutes

The traditional advice for a void-of-course Moon is to start nothing new. Umbriel's free Nothing Bell takes that literally. When the Moon goes void it shows a soft notice with the time it ends, and a two-minute quiet timer. You do nothing, tap "Nothing done", and if you like, write one line. Over a year the pauses become a logbook you can print.

• What you'll needTwo minutes; no chart and no account
• What you getThe current or next void-of-course window with its start and end in your own time, a two-minute quiet timer, a place for one line, and a printable year logbook of your pauses
• CostFree, no account required

A void-of-course Moon is the stretch between the Moon's last major aspect in one sign and its entry into the next. The tradition has long treated it as a time when things started come to little, so the usual advice is not to begin anything that matters. Most calendars stop at telling you when it is. The Nothing Bell gives you something to do with it: nothing, on purpose.

When the Moon goes void, the page shows a quiet notice: the Moon is between things until 4:17, in your own clock. Under it is a two-minute timer. You sit, or look out of a window, or just stop. Then you tap "Nothing done" and, if you want, write one line about it.

The bell can be rung at any time, not only in a void window, and a pause outside one is worth exactly as much. The timer never blocks the button. It makes no sound, ever.

There are two answers to when the Moon is void, and the page shows both. The window depends on which planets you count. The classical rule counts the Sun, Mercury, Venus, Mars, Jupiter and Saturn; the modern one adds Uranus, Neptune and Pluto, and since more planets can only mean a later last aspect, its window is the same or shorter. The Nothing Bell uses the classical one for its notice and says so, and gives the modern window beside it.

Your pauses are kept as a logbook, drawn as an engraved plate: a week to a column, a day to a square. A day with no pause is blank paper. There is no streak and nothing that says you missed the last one, and it makes sense even if you only open it on Sundays.

If you would like a nudge, you can switch one on. It is silent, and it only appears while Umbriel is open. Your pauses and lines stay private, on your device, and sync end to end encrypted if you sign in. Nothing is posted.

The engine holds two answers and the page shows both. The classical window runs from the Moon's last conjunction, sextile, square, trine or opposition to the Sun, Mercury, Venus, Mars, Jupiter or Saturn until the moment the Moon enters the next sign. The modern window applies the same rule with Uranus, Neptune and Pluto counted as well, which can only move the last aspect later, so it is the same length or shorter. The classical window drives the notice and the optional nudge, and the page names which one it is using. Both ends are shown in your own clock. The times are good to a few minutes: the Moon's longitude is measured against JPL's ephemeris at a mean of 1.3 arcminutes and a worst of 5, and the Moon covers 5 arcminutes in about nine minutes. The timer is two minutes of wall-clock time and never locks the button. The nudge, if you turn it on, is silent and only appears while Umbriel is open in a tab; it is not a push notification and nothing is sent to a server to make it happen. Each pause is stored with its date, the time you tapped, how long the quiet ran, whether the classical window, only the modern one or neither was open, and the line you wrote, if any.