Okay. Now we have the OPs clarification, the output from my code consolidating equal valued intervals is:

C:\test>935755 935755.dat
[
  ["010005", "010022", 41],
  ["010023", "012359", 0],
  ["020000", "022359", 0],
  ["030000", "032359", 0],
  ["040000", "042359", 0],
  ["050000", "052359", 0],
  ["060000", "062359", 0],
  ["070000", "072359", 0],
  ["080000", "082359", 0],
  ["090000", "092359", 0],
  [100000, 102359, 0],
  [110000, 112359, 0],
  [120000, 122359, 0],
  [130000, 132359, 0],
  [140000, 142359, 0],
  [150000, 152359, 0],
  [160000, 162359, 0],
  [170000, 172359, 0],
  [180000, 182359, 0],
  [190000, 192359, 0],
  [200000, 202359, 0],
  [210000, 212359, 0],
  [220000, 222359, 0],
  [230000, 232359, 0],
  [240000, 242359, 0],
  [250000, 252359, 0],
  [260000, 262359, 0],
  [270000, 272359, 0],
  [280000, 282359, 0],
  [290000, 292359, 0],
  [300000, 302359, 0],
  [310000, 312356, 0],
  [312357, 312359, 27],
]
[download]

Do you concur?

The (now simplified) code for this is:

#! perl -slw
use strict;
use Data::Dump qw[ pp ];

sub dhm2int {
    my( $d, $h, $m ) = unpack '(A2)*', $_[0];
    return ( ( $d - 1 ) * 24 + $h ) * 60 + $m;
}

sub int2dhm {
    sprintf "%02d%02d%02d", int($_[0]/1440)+1, int($_[0]/60)%24, $_[0]
+%60;
}

#my @data = (
#    ['010000','010010',2],['010200','010210',5],['012359','020001',3]
+,
#    ['010005','010015',1],['010207','010211',4]
#);

my @data = map[ split ], <>;

my @expd = map {
    my $in = $_;
    my $s = dhm2int( $in->[ 0 ] );
    my $e = dhm2int( $in->[ 1 ] );

    my @out;
    while( int( $s / 1440 ) != int( $e / 1440 ) ) {
        my $newe = ( int( $s / 1440 ) +1 ) * 1440 -1;
        push @out, [ $s, $newe, $in->[2] ];
        $s = $newe +1;
    }
    ( @out, [ $s, $e, $in->[2] ] );
} @data;

my( @tally );
for my $e ( 0 .. $#expd ) {
    my $r = $expd[ $e ];
    for my $i ( $r->[ 0 ] .. $r->[ 1 ] ) {
        if( !defined( $tally[ $i ] ) or $tally[ $i ] > $r->[ 2 ] ) {
            $tally[ $i ] = $r->[ 2 ];
        }
    }
}

my @res;
my $i = 0;
while( $i < $#tally ) {
    ++$i until defined $tally[ $i ];
    my $val = $tally[ $i ];
    my $start = $i++;
    ++$i while defined( $tally[ $i ] ) and $tally[ $i ] == $val and $i
+ % 1440;
    my $end = $i - 1;
    push @res, [ int2dhm( $start ), int2dhm( $end ), $val ];
}

pp \@res;
[download]