Ruby 创建日期序列

参考： https://stackoverflow.com/questions/19093487/ruby-create-range-of-dates

require 'active_support/all'
class RailsDateRange < Range
  # step is similar to DateTime#advance argument
  def every(step, &block)
    c_time = self.begin.to_datetime
    finish_time = self.end.to_datetime
    foo_compare = self.exclude_end? ? :< : :<=

    arr = []
    while c_time.send( foo_compare, finish_time) do 
      arr << c_time
      c_time = c_time.advance(step)
    end

    return arr
  end
end

# Convenience method
def RailsDateRange(range)
  RailsDateRange.new(range.begin, range.end, range.exclude_end?)
end

使用：

By hour
RailsDateRange((4.years.ago)..Time.now).every(years: 1)
=> [Tue, 13 Oct 2009 11:30:07 -0400,
 Wed, 13 Oct 2010 11:30:07 -0400,
 Thu, 13 Oct 2011 11:30:07 -0400,
 Sat, 13 Oct 2012 11:30:07 -0400,
 Sun, 13 Oct 2013 11:30:07 -0400]


DateRange((4.years.ago)..Time.now).every(1.year)
=> [2009-10-13 11:30:07 -0400,
 2010-10-13 17:30:07 -0400,
 2011-10-13 23:30:07 -0400,
 2012-10-13 05:30:07 -0400,
 2013-10-13 11:30:07 -0400]

hour, day都是一个用法