def et2jd(et): import spiceypy as sp # Convert et to jed jed=sp.unitim(et,"ET","JED") # Calculate the deltat at et deltat=sp.deltet(et,"ET"); # Add deltat to et jd=jed-deltat/86400.0 return jd
def jd2et(jd): import spiceypy as sp # Convert from JD to UTC seconds (seconds since J2000) utc=(jd-sp.j2000())/365.25*sp.jyear() # Compute deltat = ET - UTC deltat=sp.deltet(utc,"UTC"); # Compute ET et=utc+deltat return et