Natural time

formatting.php

<?php
function wp_natural_time( $timestamp, $limit = 2 ) {
	$from = time();
	$diff = absint( $from - $timestamp );
	
	if ( $diff < 1 )
		return _x( 'now', 'time ago' );

	$result = array();

	$l10n = array(
		array( YEAR_IN_SECONDS,     _nx_noop( '%s year', '%s years', 'time ago' ) ),
		array( 30 * DAY_IN_SECONDS, _nx_noop( '%s month', '%s months', 'time ago' ) ),
		array( WEEK_IN_SECONDS,     _nx_noop( '%s week', '%s weeks', 'time ago' ) ),
		array( DAY_IN_SECONDS,      _nx_noop( '%s day', '%s days', 'time ago' ) ),
		array( HOUR_IN_SECONDS,     _nx_noop( '%s hour', '%s hours', 'time ago' ) ),
		array( MINUTE_IN_SECONDS,   _nx_noop( '%s minute', '%s minutes', 'time ago' ) ),
		array( 1,                   _nx_noop( '%s second', '%s seconds', 'time ago' ) ),
	);

	foreach ( $l10n as $key => $pair ) {
		$count = (int) ( $diff / $pair[0] );
		if ( $count > 0 ) {
			$result[] = sprintf( translate_nooped_plural( $l10n[ $key ][1], $count ), $count );
			$diff -= $count * $pair[0];
		}

		if ( $limit && count( $result ) >= $limit ) {
			break;
		}
	}

	$label = ( $from > $timestamp ) ? _x( '%s ago', 'time ago' ) : _x( '%s from now', 'time from now' );
	$result = implode( _x( ', ', 'natural time separator' ), $result );
	$result = sprintf( $label, $result );
	return $result;
}