The number mandated by countries of paid vacation days varies a lot. The best would be around 30 days of paid leave + national / public holidays. These should allow members to travel home for important festivals and family gatherings, it should also give much needed rest from community chores and give you exposure to a different lifestyle.
Finally, there should probably be a variation of days for permanent and transitory members but not too vast.
The most complicated elements would be in assuring the ‘pay’ into the savings account and holidays should only really be allowed at the end of the 6 month grace period.