Required inputs
Tropical ecliptic longitude
Tropical or named sidereal frame
Ayanāṁśa method and version when sidereal
Boundary policy
Ordered execution
Work the protocol
- 1
Retain the unrounded tropical longitude.
- 2
Declare the requested zodiac frame.
- 3
Apply the named offset only to the sidereal field.
- 4
Normalize the result into [0,360).
- 5
Report distance to the next sign boundary.
Outputs
- Frame-specific longitude
- Sign label
- Boundary distance
Done only when
- Both source and derived values remain available.
- The convention is versioned.
- Boundary instability is visible.
Fail closed
Refusal conditions
- The word sidereal appears without a convention.
- Tropical and sidereal labels overwrite one field.
- The offset is chosen after interpretation.