#!/usr/bin/env ruby

DIR = '/nwp/m0'
PATTERN = 'jmagc??.tar'

files = Dir.glob(File.join(DIR, PATTERN))

# ファイルが存在しない場合
if files.empty?
  puts "535"
  exit 0
end

# 最新のmtimeを取得
latest = files.map { |f| File.mtime(f).utc }.max

now = Time.now.utc
diff = now - latest

# 出力
printf "%6.3f\n", diff