Monday Morning Blues: Employees Call in Sick Usually at Start of the Week
The study, by consultant firm Mercer, found that more than a third of all sick leave is taken on the first day of the week.
What's more, the highest rate of absence by far occurs in January, the study added.
And the most common reason for absence was musculo-skeletal problems. Following them were viral infections and stress-related illness, reports The BBC.
The findings are based on an analysis of sickness management records for 11,000 employees from a range of private sector organisations.
The study found that 13 of the 20 most popular days for sickness absence occurred in January - six of these between 2 and 9 January.
On Thursday 3 and Friday 4 January nearly 5 percent of the total employee population was absent on sick leave.
The study found that 35percent of all sick leave is taken on a Monday.
However, the lowest sick leave rate was recorded on Fridays at just 3 percent of the total.
Researcher Phiroze Bilimoria said: "Monday sickness and frequent short-term absences can be a symptom of low employee engagement and morale within certain teams or departments."
Professor Cary Cooper, an occupational health psychologist at the University of Lancaster, said: "People are doing more work under more demanding conditions so are under more stress and need more rest and recuperation.
"Some employees may feel the weekend is not enough so they take the extra day. But I suspect what is happening is people are lying about their reason for sickness absence.
"It is more believable to use back pain as a reason as often stress is seen as a four letter word. It's seen as embarrassing."