Do not want system to plan anything during gap period

Hi,

We have scenario where planning Gap is required for few months during the entire horizon for respective group of products.

e.g.

Say horizon is 1 year ( Jan to Dec. )

product A - > gap needed for July,Aug & Sep.  ( i.e. System can plan Jan to June and Oct-Dec but it should not plan anything during July to Sep)

Product B-> gap is June,July ( i.e. System can plan Jan to May and Aug-Dec but it should not plan anything during June and July )

Note:- we can receive Sales order as per customer order but will not plan and supply during these GAP period.

We thought of using Transportation Lane validity

e,g, for product A create two Lanes with different validity date.

TLane1 :- validity from 01-01-2015 till 30-June2015

Tlane 2:- Validity from 01-10-2015 till 31-12-2015

but SNP Heuristic is not respecting this ( it seems there is some flaw , might need to check sap note)

Please suggest

Thanks

Samir