Introducing the cron_format gem
The cron_format gem accepts a cron expression and returns a time.
require 'cron_format'
cron_entry = '1 * * * *'
date1 = Time.parse('2013-07-07 15:19:00 +0100')
cf = CronFormat.new(cron_entry, date1)
cf.to_time.strftime("%Y-%m-%d %H:%M")
#=> "2013-07-07 16:01"
CronFormat.new('1 15 * * *', Time.parse('2013-07-07 15:19:00')).to_time
#=> 2013-07-08 15:01:00 +0100
time gem cron_format cron