Ok, I went through the replies just now, and did some google also. For my need I actually do not need to use any modules. I have a very simple requirement! Here is the code I wrote. In this I have put incrtime as 1 sec, but I can put any number of seconds I want, so no issues there! 
#!/usr/bin/perl

use strict;
my $lat = 23.438;
my $slon= 68.000;
my $elon= 90.000;
my $clon = $slon;
my $incrlon= 0.01;
my $time = time;
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($
+time) ;
my $incrtime=1;
my $printmon;
my $printyear;
open OUTFILE,">tropic_of_cancer.gpx" or die \"Cannot open file for wri
+ting\n";

print \"Printing Header...\n";
print OUTFILE "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"n
+o\"?>\n";
print OUTFILE "<gpx version=\"1.1\" creator=\"MakeTropic\" xmlns=\"htt
+p://www.topografix.com/GPX/1/1\" xmlns:xsi=\"http://www.w3.org/2001/X
+MLSchema-instance\" xsi:schemaLocation=\"http://www.topografix.com/GP
+X/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd\">\n";
print OUTFILE "<trk>\n";
print OUTFILE "    <name>Tropic of Cancer</name>\n";
while ($clon < $elon) {
    $printmon = $mon+1;
    $printyear = $year+1900;
    print OUTFILE "        <trkseg>\n";
    printf OUTFILE ("            <trkpt lat=\"%.3f\" lon=\"%.3f\">\n",
+$lat,$clon);
    print OUTFILE "                <time>$printyear-$printmon-$mday"."
+T"."$hour:$min:$sec"."Z"."</time>\n";
    print OUTFILE "            </trkpt>\n";
    $clon=$clon+$incrlon;
    $time=$time+$incrtime;
    ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(
+$time) ;
}

print OUTFILE "        </trkseg>\n";
print OUTFILE "    </trk>\n";
print OUTFILE "</gpx>";

close OUTFILE;

[download]
It works fast and is tiny.

In reply to Solution found! by tsk1979
in thread Simple date and time manipulation by tsk1979

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