use strict;
use warnings;

my $timeLimit = '<timeLimit endTime="2016-12-28T23:59:59" startTime="2016-09-30T00:00:00"></timeLimit>'; 
my ($startTime) = $timeLimit =~ /startTime="(.*?)"/;
chomp($startTime);

if (my ($endTime) = $timeLimit =~ /endTime="(.*?)"/) 
{
    chomp($endTime); 
    print "[$startTime],[$endTime]\n";
}
else
{
    print "[$startTime]\n";
}