How are branches being used? A visualization

I really like the terminal for visualizations. There is something in its restrictions that gives it the right balance of detail for rough visualizations. The fixed width font, the ASCII character set, the small overall grid, etc, all help. I wanted to see how our developers are using branches over the last 180 days. This script gets the branches log and outputs a chart for days that had checkins by each developer. Note that a day without checkins by anyone will have no column in the chart.

The code is

#!/bin/bash

date1=$(date -v -180d +'%Y-%m-%d')
date2=$(date -v -1d +'%Y-%m-%d')
svn='svn+ssh://.../branches'

svn log --revision {$date1}:{$date2} $svn | perl -e '
  my %D = (); # dates
  my %U = (); # users
  while( <> ) {
    if ( /\| (.*?) \| (\d\d\d\d-\d\d-\d\d) / ) {
      my $u = $1;
      my $d = $2;
      $D{$d} ||= {};
      $D{$d}->{$u} += 1;
      $U{$u} = 1;
    }
  }
  my @d = sort keys %D;
  my ( $l ) = reverse sort map { length($_); } @d; # max length
  for my $u ( sort keys %U ) {
    printf( "%*s %s | ", -$l, $u, $d[0] );
    for my $d ( @d ) {
      print $D{$d}->{$u} ? "*" : "-";
    }
    printf( " | %s\n", $d[$#d] );
  }
'

# END

Update: A failing of this script is that it only shows days with activity. Days without activity by any developer will be missing from the timeline. I replaced this script with this one

#!/usr/bin/perl -w

use strict;
use DateTime;

my $svn_url='svn+ssh://.../branches';

my $stop = DateTime->today();
my $start = $stop->clone()->subtract( days => shift @ARGV || 90 );

my %W = (); # week days
my %D = (); # dates
my %U = (); # users

# initialize the dates and the weekdays hashs with days between the start and stop dates
for ( my $next = $start->clone(); $next->compare($stop) <= 0; $next->add( days => 1) ) {
 my $F = $next->strftime('%Y-%m-%d');
 $D{$F} = {};
 $W{$F} = $next->day_of_week();
}

# collect the svn usage data
if ( open( IN, "svn log --revision \{$start\}:\{$stop\} $svn_url |" ) ) { 
 while( <IN> ) {
  if ( /\| (.*?) \| (\d\d\d\d-\d\d-\d\d) / ) {
   my $u = $1;
   my $d = $2;
   if ( defined $D{$d} ) {
    $D{$d}->{$u} += 1;
    $U{$u} = 1;
   }
  }
 }
 close(IN);
}

my @d = sort keys %D;
my ( $l ) = reverse sort { $a <=> $b } map { length($_); } keys %U; # max user length

# output the chart
for my $u ( sort keys %U ) {
 printf( "%*s %s | ", -$l, $u, $d[0] );
 for my $d ( @d ) {
  print $D{$d}->{$u} ? "*" : "-";
 }
 printf( " | %s\n", $d[$#d] );
}

# output the line of mondays
printf( "%*s %*s | ", -$l, "", length($d[0]), "" );
for my $d ( @d ) {
 print $W{$d} == 1 ? "M" : " ";
}
printf( " |\n" );

# END