I do it in a combination of @RoyWissenburg and @Jordi_Visbeen.
I use a WallPlug on my bed-side cell phone charging station. When I put my cell phone on the charging station in the evening, I am marked as sleeping. When I take the phone off the charging station in the morning, I am marked as awake.
The whole thing can be modified with times and possibly motion sensors.
The advantage of this variant in comparison to IFTTT is that no connection to the Internet is required.
