How long do facebook notifications save for?

[Noel]

When you click notifications then see all notifications how long do they stay there for? Is there any possible way of deleting them?

Thanks

[My Name is Jonas]

If you click on your notifications it will take you to a big list of your most recent. If you have a lot of recent ones, old ones will be deleted, however if you have hardly any you will be able to see some from ages ago. However, if you do not sign in or check these notifications none will be deleted until you have seen them. You can delete your notifications by clicking the x when you hover over them.
Hope that was clear.