RLM Sales Agreements Processing Rules Setup

I'm looking at setting up and using RLM / OM Sales Agreements instead of standard Sales Order in the RLM Processing Rules.  I understand the parameters for the release rule, however, what exactly is the release time frame (numeric value where the unit of measure defaults to Weeks).  Does that mean if I place a 4 in the release time frame it will only place firm orders out 4 weeks, OR, does it mean every 4 weeks a new Sales Order will be created based on the Sales Agreement?  Documentation not very clear.

Based on the answer from above, if the Sales Order does change at the end of 4 weeks, will the DP reconcile the matching attributes against both or multiple sales orders?