Users will have a few months to keep using it without support, before the company switches off the service at the end of August. This is happening because Microsoft acquired the company behind Sunrise last year and put its team to work on improving Outlook instead.
According to the blog post, working on Outlook means the Sunrise team doesn't have time to support the app they created. They've been integrating popular features from Sunrise into different versions of Outlook, including a recently-released Calendar Apps feature on iOS and Android that lets users bring information from outside services into their Outlook calendar.
Sunrise users who want many of the features offered in the app can follow the Sunrise team over to Outlook, but its current capabilities aren't a perfect match for the app that's being shut down.
The Sunrise team says that they're hard at work bringing loved features from the app over to Microsoft's.
For Microsoft watchers, none of this comes as a surprise. The company said last year that it planned to shut down Sunrise.
It's a reminder that software delivered as a service can be shut down at any time, more easily than an app you've installed on your own computer. But that's the way software is heading so we'd better get used to it.