notifier.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'time_diff'
require 'twilio-ruby'

TWILIO_SID = 'twilio_sid'
TWILIO_TOKEN = 'twilio_token'
TWILIO_PHONE_NUMBER = '+447903570595'

class TwilioApi
  def client
    @client ||= Twilio::REST::Client.new(TWILIO_SID, TWILIO_TOKEN)
  end

  def send_sms(recipient_phone:, message_body:)
    client.messages.create(
      from: TWILIO_PHONE_NUMBER,
      to: recipient_phone,
      body: message_body
    )
  end
end

twilio = TwilioApi.new
countdown = Time.diff(Time.now, Time.parse('2015-10-21 20:00'), '%d, %h hours and %m minutes')
twilio.send_sms(recipient_phone: '+33670031030', message_body: "In #{countdown[:diff]} you'll talk at Web en Vert!")