How to add JulianDate objects or offsets in Skyfield

Question

The JulianDate object in Skyfield is a handy way to quickly produce and hold a set of time values in Julian Days, and pass them to Skyfield\'s at()

Answer 1

Reference here,

My solution is as follows:

from skyfield.api import load
import numpy as np
    
data  = load('de421.bsp')
earth = data['earth']
    
ts=load.timescale()
t=ts.utc(2016, 1, np.linspace(17.4329,77.4329,61), 22.8, 4, 39.3)
    
p=earth.at(t)
    
p0  = p.position.au[:,0]
p60 = p.position.au[:,60]
    
dot = (p0*p60).sum()
    
cos_theta = dot / np.sqrt( (p0**2).sum() * (p60**2).sum() )
    
print((180./np.pi) * np.arccos(cos_theta))
print("should be roughly 60 degrees")