Concepts¶ This section includes astronomical explanations and quick references for constants available in pysweph. pyswisseph to pysweph Migration Guide Dependency swap Core changes Time Zones and Julian Day Conversions Method 1: Python’s datetime with tzinfo (Recommended) Method 2: Using swe.utc_time_zone() Sidereal Zodiac and Ayanamsa Offsets The two zodiacs Ayanamsa (sidereal offset) Calculating sidereal positions swe.SIDM ayanamsa constants Bodies Major bodies and asteroids Custom asteroids and minor planets See also House Systems