Hi, transitions can be overwhelming and new experiences unsettling. The more time we have to explain and share information - about the transition itself, and the child's own emotions and views the greater the opportunity that a child will see change as manageable, familiar, better understood and potentially less scary.
When a rushed transition is unavoidable, time plays an equally important role after the event. Talking and sharing information about what happened and why, enabling the child to form an understanding about the events and again be able to put forward their views, thoughts and feelings.
Use what you know about attachment theory, positive relationships, emotional development, well-being and resilience to see how providing time helps a child through transitions.
The impact time can have on long term and short term effects is looked at on this thread
http://www.silkysteps.com/forum/showthread.php?p=41372
Hope this helps a little