fix parse issue (Ruby 1.8 doesn't like 24:00)
fix parse issue (Ruby 1.8 doesn't like 24:00)

0612800232/rufus-scheduler,railsfactory-kumaresan/rufus-scheduler,safesoftware/rufus-scheduler,moritoru81/rufus-scheduler,moss-zc/rufus-scheduler,AndBicScadMedia/rufus-scheduler,kssminus/rufus-scheduler,shutl/rufus-scheduler,jmettraux/rufus-scheduler