Calculate the moon's phase with Lunartic

I recently released my second gem, Lunartic. It allows you to easily calculate the phase of the moon on a given date. Check it out!

$ gem install lunartic
$ irb
irb(main):001:0> require 'lunartic'
    => true

# get moon data for today
irb(main):002:0> moon = Lunartic.today
    => #<Lunartic::Moon:0x007fa5028e4dc0 @date=#<Date: 2014-06-25 ((2456834j,0s,0n),+0s,2299161j)>>
irb(main):003:0> moon.day
    => 27
irb(main):004:0> moon.phase
    => :waning_crescent
irb(main):005:0> moon.percent_full
    => 0.17138763236974325

# or, get moon data for a given Date
irb(main):006:0> Lunartic.on_date(Date.new(1989, 12, 28)).phase
    => :new

Source code and more available on Github.