Sun sign boundary check
Check a birth date close to a traditional Sun-sign boundary. When the time is unknown, the full local day is checked instead of silently assuming noon.
Your inputs
Start with the example values, then replace them with your own. For tables, keep the vertical bar separators and use a dot for decimals.
Select a city to fill coordinates and the IANA time zone, or enter them manually. Verify historical local records; browser time-zone data can differ for old dates.
Astrology is for cultural exploration and entertainment. Do not base health, financial, relationship or major life decisions on these outputs. It has no scientifically established predictive validity.
Tool inputs are processed in your browser and are not submitted by this tool. Existing site analytics and advertising services have their own privacy terms.
Result and workspace
Use the start button to open your result or activity.
How it works
Find the Sun’s tropical position and angular distance from the nearest 30° sign boundary. Unknown times show the entire local-day range.
Worked example
These sample results use the original example inputs in the form. They do not change when you edit your inputs; your own result appears in the workspace.
For this example only, birth time is assumed known: 1 January 2000, 12:00, Europe/Istanbul, latitude 41.0082, longitude 28.9784. The second chart uses 1 January 2001 at 12:00 in the same time zone.
- Sun longitude: 280.2838 degrees
- Nearest sign boundary: 10.2838 degrees
| Zodiac sign | UTC instant |
|---|---|
| Capricorn | 2000-01-01T10:00:00.000Z |
Read the result carefully
Results depend on the values and assumptions shown above. Change one input at a time to see its effect. A blank or unavailable result means the data does not support a calculation; it is not zero.
Astrology is a cultural and entertainment framework, not a scientifically validated way to predict personality, health, relationships or future events. Astronomical positions do not validate astrological interpretations.
Data and calculation sources
Astronomy Engine 2.1.19 (MIT) · GeoNames (CC BY 4.0) · IANA
Geocentric tropical positions use Astronomy Engine. House options are equal and whole-sign only. City coordinates are approximate city centers from GeoNames, downloaded on 6 October 2026. Choose precise coordinates when available. Supported birth years: 1900–2100.