Before it becomes damaging?
A weekend,week, fortnight, month?
What are the consequences of leaving them? How does it effect them pyschologically in the long run?
I understand that many parents wouldn't even consider this from the basis they would miss the child. I want to discuss more what the child goes through, how it reacts and what is a safe amount of time to keep them settled secure and happy.
Obviously age and where they will stay has huge bearing on this.