I suspect that asking on a forum is not the best way of getting the data required.
Equally, different jobs will require different amounts of time to keep up to date. A construction labourer for example will take considerably less time than a software developer working for a leading software producer.
So even if you had many replies (I would suspect you would need 100's of replies to make it valid), you would also need to know (as a minimum) what job it was they did, rather than making unfounded generalisations.
Let us call "unfounded generalisations" "hypothesises".
1 Only employees of different professions and different skills that have an hour wage and earn according their working hours are interesting me.
2 It is clear that the higher skill of time working employees the more hours of work in a year he need to to keep his skills up to date.
3 It is clear that in the most cases the quantity of those working hours in a year is much less than the average quantity of working hours in a year.
My hypothesis that for high skilled employees such as a software developer, designer, engineer, doctors, teachers 400 - 600 working hours in a year is enough to keep their skills up to date.
For skilled workers 300 - 400 working hours in a year is enough.
For unskilled workers 0 - 200 working hours in a year is enough.
Let us presume that the percentage of earning according their working time peaople from all employees is 80%.
To give those people the ideal life conditions we have to give them only those numbers of working hours in a year but with the same real earning they have now.
My Global Social Project "New Saturday" gives this ability.