If the relationship is indeed over, it's good to give the person a reasonable amount of time to find a new place. What happens when married couples get divorced? Hopefully everyones mature and moving on to the point where you don't need to impose any time limits, but in the case of harsh reality, I'd give them a month to find a place and move if they have a regular job and income, and 2 months if they do not work and do not have a regular income.
Otherwise, it's up to everyone to respect and deal with eachother as adult as possible and for heavens sake don't play with or fuck eachother.
Find stable partners, not a stable of partners.
"Sometimes my whore logic gets all fuzzy"- Californication