Installation and quick test:

$>  gem install equationoftime

$> irb

require 'eot'
# => true

@solar = Eot.new
# note: you'll see a lot more in the object than an id.
# => #<Eot:0x00557b5b3187c0>

Set some parameters:

@solar.latitude = 40.7128
# => 40.7128

@solar.longitude = -74.0059
# => -74.0059

@solar.jd = Date.today.jd
# => 2458320
@solar.ma_ta_set
# => 3.402886119137273 this is ma

Now get the times

@solar.local_noon_dt.to_time.localtime("-04:00")
# => 2018-07-20 13:02:23 -0400
@solar.sunrise_dt.to_time.localtime("-04:00")
# => 2018-07-20 05:41:52 -0400
@solar.sunset_dt.to_time.localtime("-04:00")
# => 2018-07-20 20:22:54 -0400

The local_noon_dt has taken into account the equation of time. This is the true solar transit time for your location.
Try the examples included with the gem.