Bookings Log - Add the element of Time not to just log Quantity and Value but capture "Move In's" and "Move Out's

Bookings log just captures bookings in total which is fine.
I want to answer the question how much did we book? (which it does)
I also want to measure how much dollars & quantity was moved out of the current month?
or
How much dollars and quantity was moved in each month?
I may have booked $1000 dollars but also customers may have changed releases moving in from next month to the current month another $500 dollars. (We cant measure the move in’s and move out’s currently)