Euler Problem 19

My try to solve Project Euler problem no. 19 in Ruby

require 'date'

time = DateTime.new(1901,1,1)

concur = 0

while time.year < 2001 do
  if time.wday == 0
    puts time.strftime("%Y-%m-%d") + ": Yes"
    concur += 1
  end
  
  time = time >> 1
end

puts "Total concurrent: " + concur.to_s