Its generally considered good perl style to avoid doing system calls unnecessarily. In your case: instead of doung a system call to date, use localtime (or some other perl time function/module). Its generally less prone to unexpected errors and in many cases significantly faster to do it all in perl:

my ($day,$mon,$year)=(localtime(time))[3,4,5];
my $date=sprintf("%0d%02d%02d",$year+1900,$mon+1,$day);
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a quick benchmark on my system shows the localtime method is 39 times faster than the system call to date method:

 localtime:  4 wallclock secs ( 3.10 usr +  0.06 sys =  3.16 CPU) @ 30622.78/s (n=96768)
   sysdate: 31 wallclock secs ( 0.38 usr  3.65 sys + 11.15 cusr  2.36 csys = 17.54 CPU) @ 767.25/s (n=3092)

using

#!/usr/bin/perl -w
use strict;
use Benchmark;
timethese(0, {
        sysdate =>      "chomp( my \$date = `date +\%Y\%m\%d` );",
        localtime       =>      'my ($day,$mon,$year)=(localtime(time)
+)[3,4,5]; my $date=sprintf("%0d%02d%02d",$year+1900,$mon+1,$day);',
        });
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