Get the day link in WordPress post loop.

wp_day_link.php

<?php
// Day link to archive page
function prefix_day_link() {
    $archive_year   = get_the_time('Y');
    $archive_month  = get_the_time('m');
    $archive_day    = get_the_time('d');
    echo get_day_link( $archive_year, $archive_month, $archive_day);
}