There is no longer a way to compute this. While fitbit allows you to download your data, it doesn't allow you to download ALL your data. The sleep data doesn't have enough information to do the calculations. We are now missing "Time to Fall Asleep" and/or the details of how long we were restless/awake after hitting the button to start tracking sleep.
The data is now held hostage by fitbit corporation. It is still there and your can buy it from them for $50/year by subscribing to premium. Warning, though, it is only a weekly reports but each of the 7 days in the report look like the daily reports we used to get.
In the main thread over in the dashboard section of the community the fitbit moderator claims this is not an attempt to make us subscribe to premium or upgrade our trackers. You can choose to believe him if you like. Apparently sometime next week the techies will respond as to whether or not we can have our data back.
In the meantime, personally, I'm protesting by withholding my data from fitibit. I unplugged my dongle and deleted th app. If I can't have access to my data, neither will the fitbit corporation have access to my data.
