OK, in a modern 24/7 economy, the demarcation between weekday and weekend is increasingly blurred. But the jolt many feel when they return to work after a few days of R&R - that 'Monday morning feeling' - is real. And that jolt is magnified when everyone returns to work after the late-August bank holiday.
September couldn't happen at a worse time of year. The nights are drawing in, and wintry weather is just around the corner. That's SAD enough in itself, but we also need to weigh in the fact that people do something when they're on holiday that they seldom get the chance to do during the rest of the year: they reflect on their lives and their careers.
The baggage they bring back isn't just the stuff that trundles around the airport carousel - there's often a fair bit of mental baggage too. Mental baggage that gets unpacked during September.
The great news is, this convergence of seasonal factors and personal reflection presents employers with an opportunity to re-engage their staff: re-engagement that can benefit the organisation and its employees in equal measure.
Better still, back in May, the CIPD published the latest report on an ongoing study - Creating an Engaged Workforce - it is undertaking with Kingston Employee Engagement Consortium (KEEC), the conclusions of which point to the way HR can help maximise the impact of re-engagement.
And that's because the KEEC work has parallels with the research physicists have done on the atom for the past 150 years.
The word 'atom' comes from the Greek for 'indivisible', and, since the early Greek philosophers, the concept of an indivisible unit of matter had been widely accepted. Physicists had a different idea and since the 19th century have been bashing atoms together to reveal their inner structure - the Higgs boson the most recent example.
The KEEC team has been doing pretty much the same thing with the concept of employee engagement - taking what the HR community has for the past two decades defined as an indivisible unit, and pulling it apart to reveal its structure. The difference is that, where it will take decades of further research to find a practical application for the Higgs boson, HR can begin to apply the employee engagement findings right now.
The KEEC researchers first looked at what employees are engaged with at work. They identified five things: job; colleagues; organisation; line manager; and the individuals they interact with outside. An increase in engagement with each of these areas drives higher performance, with job engagement the most critical of all.
They found there are broadly two levels of engagement: 'transactional engagement', where the individual is motivated by what's in it for them; and 'emotional engagement', where individuals are motivated by the impact their work has on others.
They also discovered transactionally engaged employees are more likely to leave the organisation when compared with emotionally engaged employees, who also exhibit higher levels of performance and personal wellbeing.
These findings create a framework and a sound commercial case for the creation of a proactive re-engagement process, that should see line managers and business leaders alike sitting down with staff to explore the engagement they have with each of the five key areas, and what can be done to enhance it.
Winston Churchill famously said, "When you find a job you love, you'll never work again". Now that may be a rather lofty ideal, but if HR can add just a little sunshine to this autumn, the benefit to us all could be substantial.