The time bucket defines the frequency for checking if the projected inventory reaches or goes below the reorder point. The planning system uses the time bucket in the following ways:

• To group requirements that are due in the time bucket.
  
• To potentially reschedule a replenishment order that is due in the time bucket to fulfill a requirement.
  
• To determine when the reorder point has been crossed.
  

If you leave the field blank, then requirements that share the same date are grouped together.

Note
This field is unavailable if you select the order or Lot-for-Lot reordering policy. Each demand is then handled separately even if other demands share the same date.

The value that you enter in the Time Bucket field must be a date formula, and one day (1D) is the shortest allowed period. For more information, see How to: Enter Dates and Times.

Note
In all data formula fields, one day is automatically included to cover today as the day when the period starts. Accordingly, if you enter 1W, for example, then the period is actually eight days because today is included. To specify a period of seven days (one true week) including the period starting date, then you must enter 6D or 1W-1D.

Reference