It depends on how you stored the date and time. Is the field a MySQL DATETIME or TIMESTAMP? Or did you store epoch seconds in a INT field? If you have a choice, for a simple compare like this I would store epoch seconds and then you can test for 5 minutes easily. 
my $sth = $dbh->prepare($your_sql_statement);
my $row = $sth->fetchrow_hashref;
print "not good\n" if ($row->{date} + (60*5) < time);
$sth->finish;

[download]

If you'll be doing queries on the 'date' field (more than sorting). Then move over to the DATETIME or TIMESTAMP data type, where it will be good for the DB to know it's a time and can do SQL things with it.



grep
One dead unjugged rabbit fish later

In reply to Re: Dont allow multiple registrations or automated script problem by grep
in thread Dont allow multiple registrations or automated script problem by Nik

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.