Astrojelly guide · Updated October 11, 2026 · Calculation methods and limits
Can you generate a birth chart without a birth time?
Yes, with important limits. Your birth date gives a useful starting point for planetary placements, but a date is a whole day rather than one instant. Astrojelly's unknown-time option uses local noon as a clearly labeled reference, omits the ascendant and houses, and checks Moon-sign uncertainty. It does not quietly invent a time for you.
A chart generated this way is a partial exploration. You can learn the vocabulary and examine date-based placements, while keeping time-sensitive information open. If a planet changes signs during your local birth day, even its sign needs a boundary check.
What is reliable, uncertain or unavailable?
| Chart feature | Without an exact time |
|---|---|
| Sun and other planet signs | Often stable through a day; a sign crossing requires a check. |
| Moon sign and degree | The Moon moves noticeably. Its sign may change during the day; the noon degree is not your verified birth degree. |
| Rising sign / ascendant | Unavailable as a reliable birth placement. |
| House placements | Omitted because the starting horizon depends on time and place. |
| Planetary aspects | Noon-reference angles; exact orbs, especially Moon aspects, can change. |
How to use the free birth chart generator
- Enter your birth date and choose your birth city, rather than your current city.
- Select I don't know my birth time.
- Generate the chart and read the reference-time note before reading placements.
- If the results flag possible Moon signs, keep both possibilities open.
- Save the report only as a labeled unknown-time chart. Update it if you later find a reliable record.
If your date is January 1 in the United States, enter your local January 1 birthday. Do not convert it to a UTC date yourself: the location's historical timezone is handled by the calculator.
Can personality tell you your rising sign?
A favorite aesthetic, a selfie or a personality description cannot establish the astronomical horizon at birth. Descriptions overlap and people are more complicated than a sign label. Birth-time rectification is a separate interpretive practice, not a verified replacement for a record. Astrojelly does not claim to recover your time from a questionnaire.
Where could you look for your birth time?
Check a birth record that includes time, ask family members, or inquire about hospital records where available. Record formats and access rules vary. A remembered approximation should remain an approximation. Note whether the time is AM or PM and whether it was written in local time.
If someone recalls only a broad window, compare several times as an exploration, not as proof of a single correct ascendant. A label that changes within that window deserves an uncertainty note.
A good first reading without a time
Start with one planet that stays in the same sign throughout the day. Read its traditional themes and ask a gentle question: which of these ideas feels useful, and which does not fit my experience? Skip houses and rising-sign claims. This keeps your first chart visit curious instead of turning missing information into false precision.
Our calculation methods explain the tropical zodiac, whole-sign houses and approximate sidereal option. The Astronomy Engine documentation describes the astronomical library. Interpretations remain symbolic, not scientifically established personality or future predictions.
Try an unknown-time birth chart ↗