class Fugit::Cron

def to_cron_s
  @cron_s ||= [
    @seconds == [ 0 ] ? nil : (@seconds || [ '*' ]).join(','),
    (@minutes || [ '*' ]).join(','),
    (@hours || [ '*' ]).join(','),
    (@monthdays || [ '*' ]).join(','),
    (@months || [ '*' ]).join(','),
    weekdays_to_cron_s,
    @timezone ? @timezone.name : nil
      ].compact.join(' ')
end