From experience, 4 day week doesn’t really help. You end up doing just as much work as people on 5 days but getting paid less, getting overlooked because you’re less present, and consequently feeling resentful AND overworked. A 4 day week is great for other reasons though.
> You end up doing just as much work as people on 5 days
either you're doing too much work, or everybody else is doing too little. Cut back.
As for promotions, if you intend to do 4 days, prepare to face zero career progression in the same company - unless you're extraordinary and indispensable. But this is the price you pay for a 4 day at this point.
