Birth Time Lab

UK guide · Birth chart

Birth chart without a birth time: what you can use

You can still draw a birth chart without a birth time, and most of it holds. The Sun and the slower planets are set by the date. What needs the time is the rising sign, the Midheaven and the houses, and on some dates the Moon.

Updated

The short answer

A birth chart is a snapshot of the sky from your birthplace at the moment you were born. The planets are where they are on your birth date whatever the clock says. The time and place only set how the chart is turned: which sign is on the eastern horizon, which is overhead, and where the twelve houses begin.

So without a time you keep the sign of the Sun and of the planets, nearly always, and the aspects between them. You lose the , the and the , because those are the points that move with the turning of the Earth.

This is a common position in the UK, where a full certificate for a birth in England or Wales normally leaves the time out.

What depends on the time and what doesn't

Parts of a birth chart and whether they depend on the time of birth
Part of the chartDepends on the time?
Sun signOnly on the one date a month when the Sun changes sign.Almost never
Mercury, Venus, MarsThey move a degree or two a day, so the time rarely changes the sign.Almost never
Jupiter, Saturn and the outer planetsThey move slowly enough to hold one sign for months or years.No
Aspects between planetsThe angles between planets barely change within a day (the Moon is the exception).Almost never
Moon sign and degreeThe Moon moves about 13° a day and changes sign about every 2.5 days.Sometimes
Rising sign (Ascendant)It changes about every 2 hours.Yes, always
Midheaven (MC)It moves about a degree every four minutes.Yes, always
House cusps and the house of each planetCusps turn with the ascendant, so planets can change house.Yes, always
Descendant and ICThey sit opposite the Ascendant and the Midheaven.Yes, always

“Almost never” means that on a few dates a planet changes sign during the day. Our Sun, Moon and rising calculator tells you whether your date is one of them.

The Moon: sometimes

The Moon covers about 13 degrees in a day. On roughly four dates in ten it crosses into a new sign during the day, and then the birth time decides which sign is yours. On the other dates the Moon sign is the same all day. The Moon sign calculator shows the Moon at the start and end of your birth date and, if it changes, the local time of the change.

What to do next

  1. Use what holds. The Sun, the planets and the aspects between them are the same with or without a time.
  2. Try to find the time. See how to find your birth time in the UK.
  3. See what a range gives you. If you know roughly when, the free range check lists every rising sign that fits it.
  4. Narrow the range with your life. Dated events can pick out the most likely window inside a range; that is what the report does.

More free tools

Want more than a range? See what a full report looks like in the sample report, or get notified when UK orders open.

Astrology is a symbolic practice, not a science. Your report gives the most consistent birth-time window for the events you share. It is not a certified birth time.