sub create_snapshot_name { 

  my ($min, $hr, $day, $mon, $yr) = (localtime())[1..5];

  $mon++;      # month count starts at zero. 
  $yr += 1900; # year represents years since 1900. 

  my @fields = 
    $date_format_arg   eq 'mm/dd/yyyy'
    ? ($mon, $day)
    : $date_format_arg eq 'dd/mm/yyyy'
      ? ($day,$mon)
      : die "$date_format_arg is not a valid date format";
      
  sprintf "day=%02d_%02d_%04d,time=%02d:%02d",@fields,$yr,$hr,$min;
}