The right way to do this is to parse it into a number of seconds as would be returned by time() and then to add the number of seconds in a day times the number of days you want, and then convert it back. 

use Date::Parse; 
my $day = 24*60*60;
my $x = 3; # set this.
my $xdays = $x * $day;  
print scalar localtime(str2time("20121231") + $xdays);

[download]

Update: Changed to produce the requested format and to use the given example. Apparently I have too much time on my hands. 

use Date::Parse;
my $date = "20120516";
my $day = 24*60*60;
my $x = 24; # set this.
my $xdays = $x * $day;

# see perldoc -f localtime.
my @t = (localtime(str2time($date) + $xdays))[5,4,3];
$t[0] += 1900;  # localtime returns years since 1900.
$t[1] += 1;     # localtime returns month in range 0..11.

printf "%04d%02d%02d\n", @t;

[download]

-sauoq
"My two cents aren't worth a dime.";

In reply to Re: Adding Days To YYYYMMDD Date Format by sauoq
in thread Adding Days To YYYYMMDD Date Format by Zoomie

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