Young woman in a yellow shirt waking up in bed and looking out the window.Credit: Getty

EIGHT in ten Gen Zers have called in sick to work because they were tired, a poll found.

And two-thirds of the under-30s group did so multiple times a year.

It follows the emergence of a “Rot days” trend that involves watching TV in bed but not .

And the group was easily the worst shirkers as sleep health firm Resmed found kip sickies decreased with age.

In all, 67 per cent of Brits have pulled one.

Two-thirds of (30s to early 40s) confessed to them.

This dropped to 39 per cent of (late 40s to 50s) and 23 per cent of (people in their 60s and 70s).

Sleep expert Joshua Piper said: “Insufficient sleep costs the economy £40billion annually through lost productivity and absenteeism.

“People calling in sick to work because they’re too tired may come back to two factors: prevalence and awareness.

“Many people are experiencing persistent sleep deficits, and they may be more willing to acknowledge and act on them.”

The Office for National Statistics estimates that Britain loses 148.9million working days every year to illness — an average of 4.4 per employee.

Separately, the Chartered Institute of Personnel and Development found just a quarter of employers think under-25s are well-prepared for the world of work.

And 56 per cent said Gen Z are harder to manage than older generations.

Young woman in a yellow shirt waking up in bed and looking out the window.Eight in ten Gen Zers have called in sick to work because they were tired, a poll foundCredit: Getty