Microsoft keeps improving the way we can share our information in SharePoint Online. And in this case: external sharing.
External sharing means: sharing with people who do not have an account to access your SharePoint Online environment. Some might call this anonymous access.
Using the administration interface of Office 365 you can enable or disable this option. But this is high level. When enabled, this option allows your people to share sites and items. There are some considerations here. What are people allowed to share and is there a need to request permission before the site or item is shared? These all depend on the site-permissions combined with the Access Request Settings of the site. I won’t go into these in detail here.
But Microsoft just added another option to this functionality. Until now, you could share an item to an external user or anonymous user using a link. But you needed to disable this link yourself, when needed. Now it is possible to set an expiration period for this link.
How cool is this?
Just share a document with someone for one day, for example.