Keep the raw calculation separate from your interpretation. When birth time is unknown, omit every step that depends on houses, Ascendant, Midheaven, or angles.
Step 1Mark the profile as time unknown
Do not store noon as though it were the birth time. Keep a separate uncertainty flag and the source of any approximate range.
Step 2Calculate the start, middle, and end of the date
Use local 00:00, 12:00, and 23:59 to see which planetary degrees, Moon signs, and aspects change materially.
Step 3Keep stable planetary signs
Retain placements that stay in the same sign throughout the day. Mark degree-sensitive interpretations as approximate.
Step 4Create a Moon uncertainty range
When the Moon changes sign, preserve both possibilities. Do not choose the one that sounds more accurate.
Step 5Keep robust aspects only
Use aspects that remain within the declared orb across the time range. Remove angle aspects completely.
Step 6Omit houses, Ascendant, and Midheaven
These depend on local orientation and cannot be recovered from the date alone.
Step 7Update the whole chart when a time is found
Recalculate all houses, angles, time-sensitive aspects, and reports. Preserve the prior source history.
Quality checks
- Search official and family records before rectification.
- Treat rectified time as a hypothesis.
- Label every uncertain factor where it appears.
- Do not let AI fill missing fields.
Frequently asked questions
Is a time-unknown chart still useful?
Yes. Many planetary signs and aspects remain available, but the scope must be smaller and uncertainty visible.
Can I use solar houses?
Some traditions use them as a separate symbolic method. They should not be presented as the person’s calculated natal houses.
Can life events rectify a time exactly?
Rectification is interpretive and practitioners may disagree. Preserve the estimate and confidence rather than calling it verified.