A birth chart when you don't know your birth time
You can get a real, useful birth chart without your birth time. Your Sun sign and the signs of Mercury, Venus, Mars and every planet past them will be right, because none of them moves far in a day. What you lose is your rising sign and your houses, and sometimes your Moon sign.
Here's exactly what changes, and how to find your time if you'd like the rest.
What stays accurate
| Without birth time | |
|---|---|
| Sun sign | Right (except on the day the Sun changes sign) |
| Mercury, Venus, Mars | Right almost every time |
| Jupiter to Pluto | Right |
| Aspects between planets | Right, give or take a degree |
| Moon sign | Usually right, sometimes not |
| Rising sign | Unknown |
| Houses | Unknown |
The planets move slowly enough that a few hours either way barely shifts them. The Sun moves about one degree a day, so it only matters if you were born on the day it changed signs.
The Moon
The Moon is the fast one. It crosses a whole sign in about two and a half days, roughly half a degree an hour. If the Moon was close to the edge of a sign on your birthday, it could have been in either one depending on the hour. That happens on a bit under half of all days.
When you leave the time out, we work the chart out for midday where you were born. That's the middle of the day, so the Moon can be off by at most six or seven degrees. We mark it as approximate, and if it's near a sign boundary you'll know to hold your Moon sign loosely.
Rising sign and houses
These are the parts that really need the clock. Your rising sign is the sign coming up on the eastern horizon at the moment you were born, and the whole zodiac rises over a single day. That's a new rising sign roughly every two hours, faster or slower depending on the sign and how far north you were born.
Houses hang off the rising sign, so without it there are no houses. Rather than guess, we leave them out. A chart that says "unknown" is more use to you than one that's confidently wrong.
How to find your birth time
- Your birth certificate. In many places, including most of the US, the long-form certificate records the time. Some short-form versions leave it off, so it's worth requesting the full one.
- Hospital records. The hospital or the local records office may still have your birth notes.
- Family. A parent, grandparent or baby book often has it, even if only as "just after lunch". A rough time is better than none: it can narrow your rising sign to one or two.
- Rectification. An astrologer works backwards from big events in your life to estimate the time. It's a skill, not a lookup, so results vary.
Once you've got it, add it to your chart and everything else fills in.
Questions
Can I still get a reading without my birth time?
Yes. The reading is written for the chart you have. It won't mention your rising sign or houses, and it treats your Moon as approximate.
Should I just guess 12:00?
If you put in noon yourself, the chart will treat it as a known time and give you a rising sign and houses that are probably wrong. Tick "I don't know my birth time" instead; we'll still use midday for the planets but won't pretend the rest is known.
Is a chart without a time worth getting?
Yes. Most of what a chart says comes from where the planets are and how they relate to each other, and that's all still there.