Only show posts in the past 3 months…

Use the Return posts for various date ranges example for your 3 month request. Then might use the template tag, wp_get_archives(), after your loop to provide access to your date archives.

Related:
Stepping Into Template Tags
Stepping Into Templates
Template Hierarchy

Many thanks for the reply.

And I would add something like this code to my ‘archive.php’ script?

<?php
//based on Austin Matzko's code from wp-hackers email list
  function filter_where($where = '') {
    //posts in the last 30 days
    //$where .= " AND post_date > '" . date('Y-m-d', strtotime('-30 days')) . "'";
    return $where;
  }
add_filter('posts_where', 'filter_where');
query_posts($query_string);
?>

Can you confirm if this is correct?
Should I add the above code to my script.

I only want to display posts in the past 3 months.

Thanks

Actually shouldn’t these these two line be:

//posts in the last 90 days
    $where .= " AND post_date > '" . date('Y-m-d', strtotime('-90 days')) . "'";

Yes you can put that in your archives.php (or archive template) just before your loop that might be with something like <?php if (have_posts()) : ?>

Thanks for the reply, Michael ??

OK, so I go with:

<?php
//based on Austin Matzko's code from wp-hackers email list
  function filter_where($where = '') {
    //posts in the last 90 days
    $where .= " AND post_date > '" . date('Y-m-d', strtotime('-90 days')) . "'";
    return $where;
  }
add_filter('posts_where', 'filter_where');
?>
<?php if (have_posts()) : ?>

Would the above do?