The Moon is the fastest mover
The Moon circles the zodiac in about 27.3 days, so it spends only about two and a half days in each sign. No other body in the sky changes sign that often, which is why astrologers use it to describe the shifting mood of a day.
Its speed is not constant. The Moon's orbit is an ellipse, so it travels faster near its closest point to Earth and slower near its farthest. Some signs pass in a little over two days, others take closer to three.
How we compute the Moon right now
When you open the page, we read the current time from your device and calculate the Moon's ecliptic longitude with Astronomy Engine. The degree shown is the Moon's position within its sign, from 0 to 29.
To find the next ingress, we step forward in time until the Moon reaches the next 30 degree boundary, then narrow it down to the minute. The time you see is converted to your local time zone, including daylight saving time.
Phase and sign are two different things
The sign tells where the Moon is in the zodiac. The phase tells how much of it is lit, which depends on the angle between the Moon and the Sun. A full Moon is opposite the Sun, a new Moon sits right next to it.
Because the cycle of phases takes about 29.5 days and the cycle through the signs takes about 27.3, the full Moon lands in a different sign each month. Astrologers read the pair together: a waxing Moon in Taurus has a different flavor in tradition than a waning Moon in Taurus.
How astrologers use the daily Moon
In tradition, the Moon in fire signs is linked with energy and impulse, in earth signs with practical tasks, in air signs with talk and ideas, and in water signs with feelings and comfort. Some people like to note the Moon sign alongside their own mood to see if they notice a pattern.
There is also the idea of a void of course Moon: the stretch after the Moon's last major aspect in a sign and before it enters the next one. Tradition treats this as a quieter, less focused interval.
Your natal Moon and today's Moon
The Moon sign you were born with is fixed in your chart, and you can find it with the Moon sign calculator. When the moving Moon comes back to the exact degree of your natal Moon, about every 27.3 days, astrologers call it a lunar return. For more timing tools, see the planetary hours and the full ephemeris.