Patching Date class to parse Thai Dates. It's very basic and raw. Date.parse_thai(string)

date_parse_thai.rb

# Example:
# > Date.parse_thai '20 ม.ค. 2557'
#  => Mon, 20 Jan 2014
# > Date.parse_thai '20 ม.ค. 2554'
#  => Thu, 20 Jan 2011
# > Date.parse_thai "26 ก.พ. 2556"
#  => Tue, 26 Feb 2013
# > Date.parse_thai "26 กรกฎาคม 2556"
#  => Fri, 26 Jul 2013
# > Date.parse_thai "กรกฎาคม 14, 2556"
#  => Sun, 14 Jul 2013
# > Date.parse_thai "กรกฎาคม 26, 2556"
#  => Fri, 26 Jul 2013
# > Date.parse_thai "26 กรกฎาคม 2556"
#  => Fri, 26 Jul 2013

class Date

  def self.parse_thai(string)
    string = replace_thai_year(string)
    string = replace_thai_long_month(string)
    string = replace_thai_short_month(string)
    parse(string)
  end

  private

  def self.replace_thai_year(str)
    years = [
      ['2552','2009'],
      ['2553','2010'],
      ['2554','2011'],
      ['2555','2012'],
      ['2556','2013'],
      ['2557','2014'],
      ['2558','2015'],
      ['2556','2016']
    ]
    years.each do |year|
      str.gsub!(year[0], year[1])
    end
    str
  end

  def self.replace_thai_long_month(str)
    months = [
      ["มกราคม", "January"],
      ["กุมภาพันธ์", "February"],
      ["มีนาคม", "March"],
      ["เมษายน", "April"],
      ["พฤษภาคม", "May"],
      ["มิถุนายน", "June"],
      ["กรกฎาคม", "July"],
      ["สิงหาคม", "August"],
      ["กันยายน", "September"],
      ["ตุลาคม", "October"],
      ["พฤศจิกายน", "November"],
      ["ธันวาคม", "December"]
    ]
    months.each do |month|
      str.gsub!(month[0], month[1])
    end
    str
  end

  def self.replace_thai_short_month(str)
    months = [
      ["ม.ค.", "Jan"],
      ["ก.พ.", "Feb"],
      ["มี.ค.", "Mar"],
      ["เม.ย.", "Apr"],
      ["พ.ค.", "May"],
      ["มิ.ย.", "Jun"],
      ["ก.ค.", "Jul"],
      ["ส.ค.", "Aug"],
      ["ก.ย.", "Sep"],
      ["ต.ค.", "Oct"],
      ["พ.ย.", "Nov"],
      ["ธ.ค.", "Dec"]
    ]
    months.each do |month|
      str.gsub!(month[0], month[1])
    end
    str
  end

end