This is the amount of sleep you need to be in a good mood the next day

It's no secret that if you get a poor night's sleep, you're probably going to be cranky at work the next day - it's basically scientific fact at this stage.

But how much sleep do you need to ensure that people don't need to be walking on eggshells around you the next day? It seems you need quite a bit if this graph from Jawbone is anything to go by... Jawbone is one of the market leaders in wearable activity trackers and the company compiled the data of hundreds of thousands of users to work out how sleeping patterns affect happiness. Below is a snapshot of the infographic on Jawbone's blog post, it reveals that you need 8-9.5 hours sleep per night to be in your optimum mood the next day. The study revealed that getting more than 8 hours of sleep on a daily basis doesn't work for everybody. But it did find that on "nights that you get an extra hour of sleep compared to normal, you wake up 5% happier than you usually do". The study also found that people are twice as unhappy when they’ve lost 2 hours of sleep, than they are happier gaining 2 hours of sleep. We'll be sure to get our eight hours - at least - in future.