Extract date range of a bsp

I have used jplephem excerpt to create a smaller version of de438.bsp, specifically, to truncate the date range from today’s date (whatever that is) to one year from now. I found by accident that when I called:

t, y = almanac.find_discrete( t0, t1, almanac.seasons( ephemerisPlanets ) )

I got an exception which I determined was triggered by not having a long enough date range in the ephemeris.

Is it possible please to add an option tojplephem or maybe an API call to SpiceKernel which gives back the start/end date ranges?

[brandon-rhodes]

Thanks to:

e93f5db346588381ba6cf0923141206bf103de36

— it will now be easy to inspect and print ephemeris epoch times in the next version of Skyfield. You can try it out now with:

pip install https://github.com/skyfielders/python-skyfield/archive/master.zip

Enjoy!

[brandon-rhodes]

This function:

from .timelib import calendar_date

— should give you a quick way to convert that date into something in the Gregorian calendar. For the future, I’ll try adding functions (maybe .initial_epoch and final_epoch, to match the SPK documentation?) that can produce a Skyfield date directly from those values. Thanks for the idea!