require "date" # 2017/8/19 start_date = Date.new(2017,8,19) => #<Date: 2017-08-19 ((2457985j,0s,0n),+0s,2299161j)> #today end_date = Date.today => #<Date: 2017-11-03 ((2458061j,0s,0n),+0s,2299161j)> # diff (end_date - start_date).to_i => 76 # to_s end_date.to_s => "2017-11-03" start_date.to_s => "20…</date:></date:>