How long to leave a 301 redirect

[consciouspnm]

When I first set the website up I used extended info pages. After browsing these forums for a bit I saw the light and scrapped them and put a 301 redirect in .htaccess This was months ago so I tidied up the .htaccess file at the weekend and now Webmaster tools is giving me 404 errors in the old info pages. How long to I need to keep the rediect there?

[grantglendinnin]

Until no search engine has indexed them, there's no reference to them on your site, and until there's no link to the page anywhere that will lead anyone or anything to 'click' on the link to arrive on that page. In other words, indefinitely.