Date for closing RQ/RP/* FY2015 visas?

When is the most probable date of ending the FY2015 Regular Quota, receipts?
By checking previous years and the number of petitions they would process, my guess is somewhere between May 27th and June 20th. Does anybody agrees or have a different perspective?

U can keep hopes until the packet is returned… RQ/RP takes time… Last time they got receipts till june last week