What is a nine-day fortnight and could it replace the four-day week?

Discussions surrounding the elusive work-life balance have been ramping up in recent months, with many companies introducing greater flexibility to working hours, including implementing a four-day week.

But now there’s a new kid on the block – the nine-day fortnight. This flexible working arrangement could be the perfect solution for those who want to move away from the five-day week, but who aren’t ready just yet to lose an entire day four times a month.

At the start of November, 17 organisations began trialling the nine-day fortnight as part of the UK’s second four-day week trial. Let’s take a look at how it works, and how you can implement it in your organisation.

What is a nine-day fortnight? 

Simply speaking, a nine-day fortnight is the concept of condensing 10 days’ work into nine, giving you one day off every two weeks.

Staff would work the same hours they are contracted to over a two-week period, but would work extra hours for the first nine days of the two weeks, allowing them to take Day 10 off.

How do you calculate a nine-day fortnight? 

To calculate a nine-day fortnight, you’ll need to first work out a worker’s contracted hours for a two-week period.

For example, if a worker is contracted to work eight hours per day, their contracted hours for two weeks would be 80 hours (on the assumption that they work five days per week).

In order to work a nine-day fortnight instead of 10, the worker simply needs to make up the eight hours they will take off. 

For example, they could work for an extra hour Monday – Friday in Week One and then Monday – Wednesday in Week Two in order to take the Friday off that week.

Most businesses will introduce a cycle structure so that you can be clear on what is Day One, and what is Day ten, aka the day off.

How do I work a nine-day fortnight? 

If you’re an employee and you think a nine-day fortnight could be the ideal working setup for you, then you’ll need to sit down with your managers and HR department.

While ultimately the decision will lie with your organisation, thanks to the Flexible Working Bill that came into effect in April 2024, employees no longer need to have worked at a business for 26 weeks or more to request flexible working arrangements and can instead ask from day one.

If you want to pitch a nine-day fortnight to your manager, do your research and clearly explain the concept, reiterating that you’ll be working all of your contracted hours over the two-week period.

Is it the new four-day week?

Another common flexible hours option is the four-day week, but a nine-day fortnight isn’t the same thing.

A four-day working week tends to remove a working day altogether.  Whilst employees will often work longer hours for the four days, they’re unlikely to make up the full day that’s lost.

In a nine-day fortnight model, however, employees will work the exact same hours over a two-week period, with the hours condensed down to nine days.

A nine-day fortnight therefore can often have less impact on the day-to-day running of a business and on staff productivity. 

At the start of November, the UK began a new four-day week trial. Many participants will work a nine-day fortnight, suggesting it could be a good compromise for firms that aren’t comfortable with a four-day week, but want to explore alternative flexible work options.

Final thoughts

Introducing a nine-day fortnight model could come with a host of benefits, including better staff morale and wellbeing, increased productivity and longer staff retention. 

Changing the working model of an organisation can be daunting, but a nine-day fortnight shouldn’t introduce too much disruption, and could actually result in major mutual benefits for employers and employees.

If you’re thinking about introducing a more flexible model, take a look at our guide to every flexible working approach to help you figure out which one is right for you.

Lucy Nixon - content writer

With 10 years experience in the digital marketing industry, Lucy is a content writer specialising in ecommerce, website building and all things small business. Her passion is breaking down tricky topics into digestible and engaging content for readers. She's also committed to uncovering the best platforms, tools, and strategies, researching meticulously to providing hand-on tips and advice.