Is the colon required in the offset for your purposes? If not:

perl -E '
use POSIX;
say strftime "%Y-%m-%dT%H:%M:%S%z", localtime();
' 
2014-03-31T23:37:59-0700
[download]

If you want the colon and no zero-padding, you could grab the offset by itself (strftime "%z", localtime();), throw a colon in it and drop the leftmost digit if it is 0. Or there might be an easier way.

Allowing the leading zero to be dropped would be a bad choice of format as it would no longer be an iso8601 timestamp. (Adding a colon is fine.)

Thanks but I need a colon in timezone as need to put it in a xml file which understand that notation only.

then do it in two steps :) second step being adding colon to timezone

use DateTime;
local $\ = $/;
print DateTime->now( qw[ time_zone local ] )->strftime('%F-%H-%M-%S%z'
+);
print DateTime->now( qw[ time_zone Greenwich ] )->strftime('%F-%H-%M-%
+S%z');
__END__
2014-03-31-23-45-31-0700
2014-04-01-06-45-31+0000
[download]

Those aren't in the format the OP requested, and despite your "tag", those aren't valid iso8601 timestamps either.

Those aren't in the format the OP requested, and despite your "tag", those aren't valid iso8601 timestamps either.

And then what happened?

Not for nothing, but yes, it is valid iso8601 ... and so what if its not 100% what the OP wants?