This problem isn't exclusive to the private sector. Although some public servants enjoy the benefit of flextime or paid overtime, unpaid overtime is an expectation for most Australian Public Service executives. A Community and Public Sector Union survey of female public servants published earlier this year found almost two-thirds worked extra hours, while a poll of ACT government staff revealed that 20 per cent considered it "very difficult" to finish their work in ordinary hours.

Few executive-level public servants would bemoan the occasional hour of overtime. It comes with the job and is factored into the remuneration. Yet when work piles up and staff are asked to work late nights and weekends to meet deadlines, a range of vexing employment law considerations arise.

First, the Fair Work Act provides that an employer cannot require a full-time employee to work more than 38 hours a week plus "reasonable" extra hours. This statutory prohibition is also reflected in APS enterprise agreements. An employee can refuse to work unreasonable extra hours and is protected from adverse action. The Health Department's new agreement, for example, explains that "such refusal will not prejudice the employee's employment".

The act then sets out criteria for determining whether extra hours are reasonable. These include health and safety risks, the employee's personal circumstances, business needs, whether the employee is entitled to overtime pay and the nature of the employee's role. The explanatory memorandum indicates that a flexible and commonsense approach should be taken; in some cases "a single factor will be of great importance", while in others it will be necessary to undertake "a balancing exercise between factors".

Australian courts have considered what constitutes unreasonable extra hours on several occasions. In 2009, the Federal Magistrates Court held that a four-hour increase in rostered weekly hours for mine workers, from 40 to 44, was not unreasonable despite the aggrieved employee contending that family commitments prevented him from completing extra hours.

Federal Magistrate Michael Jarrett reached the opposite conclusion in a 2013 dispute, finding that an involuntary, three-hour-a-week increase in working hours, unsupported by any compelling business reason and undertaken in a non-consultative "the-employer's-way-or-the-highway" manner, was unreasonable. Jarrett's judgment was affirmed on appeal: the Federal Court emphasised that "each case must be considered on its own facts".

Most recently, in 2014, a photographer – already working 45 to 50 hours a week – was requested to work "whatever hours it took, if it's seven days a week, you have to do it". The Federal Circuit Court found that, despite the applicant being "a managerial employee, paid on a salary in excess of the industry norm, and that the nature of the work required some evening and weekend work", such demands were patently unreasonable. "It is doubtful," Judge Dominica Whelan mused, "that a request to work 'whatever hours it takes' from a base which already exceeds the statutory standard could ever be reasonable."

Beyond the Fair Work Act, there are possible common law and statutory limits on overworking employees. It may be that demanding unreasonably long hours could constitute a breach of an employers' contractual or tortious duty of care to an employee. Such arguments have been successful in British courts, though the High Court of Australia rejected them in a case involving a psychiatric injury inflicted as the result of an excessive workload.

It is undisputed, however, that extreme requirements for overtime could put an employer in breach of its work health and safety obligations under harmonised state and national legislation. While individual employees are unable to take personal action, appointed health and safety representatives, unions and regulators are all empowered to take steps in response to compliance failures. As a practical matter, though, such action is unlikely to occur unless overwork is systematic and acute.

To some, these concerns may seem hyperbolic. "Overpaid public servants worrying about a few hours of extra work – how rich," one line of reasoning might go. But the personal, familial and societal impacts of rampant overwork should not be understated. And while in theory the legal protections outlined above seem sound, in reality the inclination to work extra hours in a desire to meet far-fetched performance indicators can be overwhelming.

A 2010 report from The Australia Institute observed that widespread overtime "has significant implications for the health of both individuals and relationships and plays an important role in restricting the opportunities for those who desire additional work". Although some workplaces are improving flexibility in working arrangements, "at an economy-wide level there remains a substantial mismatch between the hours that people want to work and the hours they are working. Unless concerted action is taken by all of those with an interest in this issue – workers, employers and policymakers – the scourge of time poverty is likely to persist."

In an ideal world, every day would be Go Home on Time Day. Until that utopian future arrives, employees must be aware of their rights and employers should carefully manage workloads while being responsive to individual concerns about excessive overtime.

John Wilson is the managing legal director at Bradley Allen Love Lawyers and an accredited specialist in industrial relations and employment law. He thanks Kieran Pender for his help in preparing this article. john.wilson@ballawyers.com.au