Ask any parent of a small child or baby how much sleep they're getting, and you run the risk of having them dissolve into exhausted tears.
It's not just babies which have a knack of robbing you from your eight hours.
'Set' bedtimes for kids at any age can be derailed, not only by attempts to stay up, but also by family life, growth spurts, developmental leaps, sleep regression, teething and illness.
So a bedtime 'guide' chart which has been shared by hundreds of thousands of parents has understandably struck fear into the hearts of the majority of them.
If it is to be believed, then it means a lot of us have been getting it wrong.
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Posted on the Facebook page for Wilson Elementary School in Kenosha, Wisconsin, the chart has risen to parents' attention again - and divided them.
While many mums and dads were despondent and disbelieving, there were plenty who agreed with what the guidelines were trying to achieve, and argued that routine was crucial for kids.
Katie Phillips praised it saying, "This is a pretty good chart," but did agree things got trickier during the summer months.
Kirsten Scherer did not agree, however, adding, "I'm sorry, but this chart is absurd. Who puts their kid to bed at 6:45?"
Others argued that it was too rigid, or that it shouldn't apply if a child still naps during the day, or that it simply wasn't possible with work and / or domestic committments.
Wherever you as a parent stand on bedtimes, it's clear that as an issue, it's still an important and prevalent one.
