Revising scheduled forecast data to a common start date.  The start date is often referred to as “time zero”.   The effect is to remove any pre-determined scheduling of the forecasts to a neutral state, where it is free to be rescheduled by a different process.   An example might be to take existing plan forecast data and return it to start in its first year, so that a portfolio optimization can re-schedule it in response to constraints, etc.  Another use for this is in type well profile analysis, where all production curves are aligned to the same “time zero” start.