|F1 Savannah cats snoozing. Photo copyright A1 Savannahs|
I believe that there is a lot of incorrect information on the Internet with one author copying from another ad infinitum and eventually creating fact out of fiction.
As far as I'm aware, there has only been one definitive assessment as to how long a cat sleeps and that was with respect to the lion and the lion slept for about 9 hours daily on average. There is a lot of discussion on the Internet about how long the lion sleeps, as well, and that discussion is misleading because you will see times as long as 19 hours and people claiming that the lion sleeps the longest of all the world's cats. I don't believe it. It is more or less Internet chatter.
The conventional viewpoint is that the domestic cat sleeps for around 14 or 15 hours per day. As I mentioned, the domestic cat will only sleep a total of about 8 hours per day and this is made up of small sessions of sleep. It is not continuous as is the case for people.
Some domestic cats, particularly full-time indoor cats, will spend a lot more than 15 hours a day apparently sleeping when in fact they are simply killing time by resting because often there is little to do and the owner of the cat is probably too busy and preoccupied with other things to provide entertainment and stimulation.
I have written a page about this topic which expands on what I have written here.