Constants for expressing human-readable intervals in new #WordPress are very useful:
define( 'MINUTE_IN_SECONDS', 60 );define( 'HOUR_IN_SECONDS', 60 * MINUTE_IN_SECONDS );define( 'DAY_IN_SECONDS', 24 * HOUR_IN_SECONDS );define( 'WEEK_IN_SECONDS', 7 * DAY_IN_SECONDS );define( 'YEAR_IN_SECONDS', 365 * DAY_IN_SECONDS );
Example:
wp_cache_add($key, $data, 'default, 5 * DAY_IN_SECONDS);