Changing "this day/this week/etc." to "of last 24 hours/of last 7 days/etc."

Hi,

I'm trying to change any place that has "this day/this week/etc." text to "of last 24 hours/of last 7 days/etc." The places I'm stuck on are for the Titles and RSS feeds in vote_up_down.module. I see the code I need to change for one of the titles, on the second line:

function vote_storylink_page_interval_top($interval) {
<?php  drupal_set_title($title = t('Most popular news this @epoch', array('@epoch' => t($interval)))); ?>
  $epoch = strtotime("-1 $interval");
  $sql = db_rewrite_sql("SELECT n.nid, n.created, v.content_id, v.value, v.tag, v.function FROM {node} n INNER JOIN {votingapi_cache} v ON n.nid = v.content_id WHERE n.type = 'storylink' AND n.status = 1 AND n.created >= %d AND v.tag = 'vote' AND v.function = 'sum' AND v.content_type = 'node' ORDER BY v.value DESC, n.created DESC");
  $result = pager_query($sql, variable_get('default_nodes_main', 10), 0, NULL, $epoch);
  while ($node = db_fetch_object($result)) {
    $output .= node_view(node_load($node->nid), 1);
  }

It's obviously grabbing a value for "day", "month", etc, but I don't know how to replace it efficiently. Many thanks to anyone who can help!