How to run a Four Day Week experiment

The Four Day Week (FDW) movement was sparked by Andrew Barnes from Perpetual Guardian after he read an Economist article on research showing workers were typically only productive for 1.5-2.5 hours a day. Barnes was inspired to see if allowing his employees one full day off each week would encourage them to increase their productivity on the remaining working days to maintain the same output (all they needed was an extra 40 minutes on the remaining four days!). Since the success of this trial, organisations all over the world have implemented the FDW, including Inventium, in 2020.


To trial a FDW that will improve productivity and wellbeing through working four standard days a week, with no reduction in pay.


  • A facilitator to lead the FDW experiment
  • Leadership support and role modelling
  • A trial period (we recommend six months)
  • A method for capturing survey data on your people’s productivity and wellbeing (We use Survey Monkey and Peakon)
  • Shared documents to discuss questions, decisions, and survey result updates (We use Google Docs and Dropbox)


  1. Decide if you are going to run a trial in just one team/department or across the entire organisation. We are a small team so we decided to have the whole organisation do it at once. Unilever and Microsoft are examples of organisations that decided to run a trial in just one area (New Zealand for Unilever, Japan for Microsoft).
  2. Run a pre-mortem to identify risks and opportunities, and engage your people in designing how the FDW will work for your organisation (see this experiment).
  3. Based on your pre-mortem, the facilitator and leaders should make key decisions about how the FDW trial will work at your organisation - for example, will everyone take the same day off each week or will it be self-decided? (At Inventium, we all take Friday off) Will part-time workers be able to participate? What does this mean for your clients/customers? Anything else that needs to be considered to mitigate the risks shared through your pre-mortem?
  4. Give the initiative a name. You might like to crowdsource suggestions from the team. We named our FDW the Gift of the Fifth to signify the intention behind it (check out our explanation in the Policy document below - Step 13).
  5. Set a date to start the trial. We recommend allowing a few weeks to prepare your experiment, allow people to shuffle their diaries and do whatever else they need to do before going live.
  6. Design your FDW experiment, including hypotheses, metrics, methods for gathering data and taking a baseline. Here is what we did at Inventium:
    1. We set the following hypotheses:
      1. Employees will participate in the FDW
      2. The FDW will reduce 'intention to leave' (outcome variable)
      3. The FDW will increase self-reported productivity, job satisfaction, engagement, wellbeing, energy and (decrease) stress (outcome variables)
      4. The FDW will not have a negative impact on Inventium achieving company goals v. The FDW will not decrease team connectedness, collaboration or cohesiveness
      5. The FDW will not negatively impact client responsiveness
    2. We gathered the following data (we use a monthly Peakon survey for engagement. For everything else, we created surveys using SurveyMonkey):
      1. Quantitative:
        1. Weekly:
          1. Participation in the FDW
          2. Client responsiveness
          3. Cohesiveness
          4. Collaboration
        2. Monthly: (using an existing engagement survey methodology at Inventium)
          1. Team Connectedness
        3. Every two months:
          1. Outcome variables listed above
        4. At the end of the six months:
          1. Achievement of company goals
      2. Qualitative:
        1. Updates in weekly team meeting - opt-in to share if you took the Gift last week and what you used your time for
        2. Interviews with the team half-way through the trial to see how everyone was going and provide support where necessary
        3. An open-ended question requesting feedback in the survey sent out every two months
  7. Share the decisions you have made about the FDW in a document that all employees can access for future reference (here’s something we created at Inventium to do this).
  8. Create a shared spreadsheet to house your experimental data and hypotheses, and also as a place where people can add FAQ throughout the trial. The facilitator should address any questions as they arise.
  9. Run productivity training. Equip your people with tools to be more productive so they are empowered to take their day off. You might like to try our Workday Reinvention Program! At Inventium, our Founder Dr Amantha Imber shared her top 10 tips (we had already completed our own productivity training).
  10. Launch the trial on your set date, and confirm the end date of your trial (we started in the first week of July 2020 and ended 6 months later).
  11. Throughout the trial, capture data as per your experimental design (see Step 6 above). Update your shared spreadsheet as the data comes in and also send email updates to keep your people across how the trial is going.
  12. At the end of the trial period, capture your final data, share the outcomes and learnings with your people and decide whether the trial will be made permanent. We suggest tweaking how the FDW works at your organisation based on feedback and keeping up data collection on a semi-regular basis to ensure it continues to add value for your people and organisation.
  13. Create a FDW policy for future reference by existing and future employees. Here is ours for inspiration.


The FDW trial is a perfect way to minimise the risk of failure and maximise your chances of success in implementing this HR initiative. Co-creating the FDW with your people increases engagement and minimises uncertainty around the change. Taking a data-driven approach via experimentation ensures you can learn what is working and what isn’t when testing a FDW at your organisation. It also means that when you find something isn’t working as expected, you are encouraged to iterate rather than being beholden to decisions made in the past with limited information.