This has been discussed at length on this forum ever since the announcement about Oct 11. I and several others believe that it means you must have satisfied the eligibility criteria under the new rules (C6) on Oct 10th, which makes you eligible to apply on 11th. Anyone who completes 3/5 years in Canada *ON* October 11th needs to wait one more day and apply on Oct 12th.
Basically, the day you apply (sign) cannot count as 1 day of physical presence towards 1095 days. That being said, no harm in waiting and applying on Oct 12th to be perfectly safe.