Handle Julian Dates in Ruby

I recently had to deal with parsing Julian Dates on a project. This was my first time seeing this in the wild and to my surprise, Ruby has some handy utilities on Date for converting to/from Julian Date Numbers.

Parse a Julian Date Number into a Date

Date.jd(2459936)
#=> #<Date: 2022-12-22 ((2459936j,0s,0n),+0s,2299161j)>

Convert a Date Object to a Julian Date Number

Date.new(2024, 02, 29).jd
#=> 2460370

https://en.wikipedia.org/wiki/Julian_day