So this exists. The goals are

• people get financial security by having more than one employer.
• people can change jobs and careers more fluidly. they can experiment with new careers without risk.

There is also an idea I've written about before, of everybody serving 1 year conscription in the civil service. (I now know this is not a completely new idea.) The goals are

• Give a critical mass of people insight into how the public service really works, what are the weaknesses and problems, what is it like to do these jobs. This could lead to societal improvement
• Allow people to try new careers
• Make corruption more difficult. For example if the police were routinely torturing people or record holders destroying peoples documents, it would be much more difficult to keep it a secret, with new uncorrupted people arriving in the office each year, observing all, and leaving again.

It is debatable if this should be optional. If it is not, it could delay people starting their real careers by forcing them to do a job they resent. Or it could be educational, changing peoples minds about their planned career path.

All of the above is good for individuals, for society, and for employers.

Now combine the two ideas. Like this:

Friday is designated an overwork day. Employees get a legal right to not work Fridays, for any or no reason, with a proportional salary cut.

Employers can hire new people to work Fridays only, with the eventual hope of poaching the employee.

Employees also get the right to 6 months unpaid leave. This can be used to try out working in the civil service or another employer.

This combined policy has even greater benefits.