global $my_exclude_categories, $my_exclude_categories_rss;

$my_exclude_categories = array( 1, 3 );
$my_exclude_categories_rss = array( 1, 3 );

function next_week_link( $label = 'Next Week', $display = true ) {
	if ( $display )
		echo get_week_link( $label, 'next' );
	else
		return get_week_link( $label, 'next' );
}


function previous_week_link( $label = 'Previous Week', $display = true ) {
	if ( $display )
		echo get_week_link( $label, 'previous' );
	else
		return get_week_link( $label, 'previous' );
}



function get_week_link( $label, $next_or_previous = '' ) {
	
	$archive_month = get_this_week( $next_or_previous );
	
	if ( $archive_month ) {
		
		$paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
		if ( $next_or_previous == 'next' ) {
			--$paged;
		}
		if ( $next_or_previous == 'previous' ) {
			++$paged;
		}
		
		return '<a href="' . get_pagenum_link( (int)$paged ) . '">' . $label . '</a>';
	}
	return '';
	
}


function get_this_week( $next_or_previous = '' ) {
	
	$arc_week = array();
	$paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
	
	if ( $next_or_previous == 'next' && $paged == 1 ) {
		return $arc_week;
	} elseif ( $next_or_previous == 'next' && $paged > 1 ) {
		--$paged;
	}
	
	if ( $next_or_previous == 'previous' ) {
		++$paged;
	}
	
	$limit = ( $paged > 1 ) ? ' LIMIT ' . ( $paged - 1 ) . ',1' : " LIMIT 1";
	
	global $wpdb, $my_exclude_categories;
	$where = get_posts_by_author_sql( 'post' );
	//$where = "WHERE post_type = 'post' AND post_status = 'publish'";
	
	$join = '';
	$order = 'DESC';
	$week = _wp_mysql_week( '`post_date`' );
	$tax_query = $tax_query = array(
		array(
			'taxonomy' => 'category',
			'terms' => $my_exclude_categories,
			'operator' => 'NOT IN'
		)
	);
	$tax = get_tax_sql( $tax_query, $wpdb->posts, 'ID' );
	$tax_where = $tax['where'];
	$query = "SELECT DISTINCT $week AS `week`, YEAR( `post_date` ) AS `yr`, DATE_FORMAT( `post_date`, '%Y-%m-%d' ) AS `yyyymmdd`, count( `ID` ) AS `posts` FROM `$wpdb->posts` $join $where $tax_where GROUP BY $week, YEAR( `post_date` ) ORDER BY `post_date` $order $limit";
	
	$arcresults = $wpdb->get_results( $query );
	
	if ( $arcresults ) {
		
		$arc_w_last = '';
		$arc_week = '';
		if ( $arcresults ) {
			foreach ( (array)$arcresults as $arcresult ) {
				if ( $arcresult->week != $arc_w_last ) {
					$arc_year = $arcresult->yr;
					$arc_w_last = $arcresult->week;
					$arc_week = get_weekstartend( $arcresult->yyyymmdd, get_option( 'start_of_week' ) );
				}
			}
		}
		
	}
	return $arc_week;
}


add_action( 'pre_get_posts', 'weekly_pagination' );
function weekly_pagination( $query ) {
	global $my_exclude_categories, $my_exclude_categories_rss;
	if ( !is_admin() && $query->is_main_query() ) {
		if ( is_home() ) {
			$query->set( 'nopaging', true );
			$query->set( 'category__not_in', $my_exclude_categories );
			add_filter( 'posts_where', 'new_posts_where' );
		}
		if ( is_feed() ) {
			$query->set( 'category__not_in', $my_exclude_categories_rss );
		}
	}
}


function new_posts_where( $where ) {
	if ( !is_admin() ) {
		global $wpdb;
		$week = get_this_week();
		
		$start = $end = false;
		if ( $week ) {
			
			if ( $week['start'] ) {
				$start = date( 'Y-m-d H:i:s', $week['start'] );
			}
			
			if ( $week['end'] ) {
				$end = date( 'Y-m-d H:i:s', $week['end'] );
			}
			
			if ( $start && $end ) {
				$where.= " AND $wpdb->posts.post_date >= '$start' AND $wpdb->posts.post_date <= '$end'";
			}
			
		} else {
			$where.= ' AND 1=0';
		}
	}
	return $where;
}