I imagine that one way to reduce the way the financial impact of working 80% is to wait till you get a pay rise, (or move to a higher paying role at a new company), and make the switch at the same time, so you never feel like you're financially worse off than you were before.
Some people believe that jobs give meaning to human lives. Now that your life is 20% less meaningful, how do you cope with the existential despair? :D
Surely there are diminishing returns to meaning obtained per work time, and with 80% of the work you get like 95% of the meaning.
And given that you now have much more time for coping, overall that's probably a pretty positive deal!
I made very similar experiences. Work does get quite a bit more hectic, as everyone around you now works at +25% speed and you have less focus time per work time.
It's also easy to fall into the double counting trap, where you think "oh, I've got an extra free day now, so I can work on projects! And relax! And spend time with my family! And naturally, errands and appointments will also fall on this day. And I can travel on the longer weekend. Etc. Etc." without realizing that these things are battling out a zero sum game over that extra day. It takes a lot of awareness and discipline to use it intentionally for a longer time without falling back into the default of doing on that free day what you otherwise would have crammed into the evenings.
There is a similar effect (without the salary considerations) from working remote instead of commuting. Before I went full time remote my commute had gone up to about 1.5 hrs each way. For me, going remote meant an extra 15 hrs/wk available for other things.
A year ago, I decided to reduce my employment level from 100% to 80% and to take Fridays off.
My main motivation was to have some time for myself: Relax, reduce my stress level from work, have more time for side projects, do more sports, and maybe spend more time with my wife without the kids. This was only partially successful as there were a few things I had not realized beforehand.
I’d like to describe my experience, and will focus on the effects this change had on my work, financial situation, side projects, and personal life / health.
To give some background, I’ll start with my personal situation: I have two small kids and spend the mornings, evenings and the weekends with them. During the day I’m working. This schedule does not leave much time for myself. When the kids go to bed in the evenings, I’m usually too tired to do anything meaningful.
While I worked 80%, I put the kids to childcare during my day off.
Work The four days I spend at work have become very fast-paced and concentrated. There is less time for chats and social interactions at work, and I’m more focused on getting stuff done.
Some activities do not reduce by 20% but have a fixed time requirement per week or month (e.g., weekly team meetings). These will now fall in 4 instead of 5 days, leaving over-proportionally less time to get work done.
Additionally, this increased density of meetings during the 4 days means there will be fewer long time blocks available to get deep work done.
Your colleagues need to adjust, e.g., they need to know that you don’t work on Fridays. While you can make this clear by putting a blocker in your calendar, they also need to consider your reduced availability in their planning.
There is also a risk that management and your colleagues only slowly adjust their expectations to your reduced level of output.
As a result, I believe it is proportionally harder to be productive at the new employment level, while at the same time your colleagues and management may only slowly adjust.
Financial situation The obvious first-order impact of reducing your employment level by 20% is that you will earn 20% less salary.
However, there are a few less obvious things to consider in this calculation:
The income tax progression means the top 20% of your income are taxed higher than the remaining 80%, meaning that after deduction of income tax, a reduction of 20% gross salary will translate into a smaller reduction in net salary (e.g., an 18% reduction).
There may be a reduced cost of childcare if you decide to look after your kids yourself on the day off.
You may have more time to make cost-conscious decisions, e.g., spend more time planning holiday trips and get better deals.
There may be employment benefits that are independent of your employment level. In fact, there may even be employment benefits that only trigger if your (or your family’s) income is below a certain threshold.
It’s also important to know that a reduced salary will lead to a reduced pension contribution.
Perhaps most importantly though, there is an overproportional impact on money saved: If you save, say, 30% of your salary at 100% employment, you will only save 10% of your original salary at 80% employment. In this example, after your reduction to 80%, you only save 1/3 of what you saved at 100% employment.
Side projects I found it very difficult to get longer projects done on one day per week. The progress of a few days of work will be easily spread out over a few months. This requires you to be very patient, and it’s easy to lose much time finding out where you left off last week.
Good upfront planning of the day off is therefore required, otherwise you risk that you don’t don’t achieve anything meaningful.
I could get a few small side projects done that were manageable within about one or two days, but I did not complete any project that would require a time investment longer than a few days.
A potential alternative to taking one day off every week could be to work 5 days a week for a few weeks and then take a full week off to only focus on a project for an extended period of time.
Personal life / Health I felt an overall much lower stress level from work. There is more time to take care of your health, like going outside and doing sports. I went running 3-4 times per week instead of 1-2 times, and lost 6kg.
My wife and I also managed to spend some time as a couple without the kids, like going to the cinema, to brunch, lunch, walks, etc.
To conclude, it’s probably a good idea to consider upfront what your main goals are (e.g., running more often, reducing stress from work, more time for side projects, more time with your partner), and to consider what are possibilities of achieving them.
Employment reduction is probably only one way among various other alternatives.