Is it recommend to amend Recipe in mid of the month - Cost Roll up would be affected?

Hello All,

Application Version 12.1.3 & OPM Standard Costing Method

Is it recommend to update Recipe & Validity Rule's effective date in mid of the month?

What will happen when we run Cost Roll up for the following scenario?

ITEM1 - 'Recipe Ver 1' - Effective Start Date -'01-JAN-2016' | End Date - '15-Jul-2016'

ITEM1 - 'Recipe Ver 2' - Effective Start Date - '17-Jul-2016' | End Date - '31-Dec-2016'

Questions:

1] Cost Roll up would run without error for Jul period?

2] If [1] is Yes, Which recipe will be picked for cost Roll up?

3] If both recipes considered for roll-up, Variance would be posted correctly?