Notice Only Starts From Filing ESA Form 1:

In Wood v CTS of Canada  Co. ( 2017 ONSC 5695, Justice Sproat held that in a mass termination under the ESA of Ontario that the employer only gets credit for working notice, under both the ESA and the common law of reasonable notice, from the date that the Form 1 is filed with the Ministry of Labour and then is posted in the workplace.

Furthermore, in any week of working notice that the employee works in excess of the maximum overtime ( usually 48 hours ) that week does not count as working notice.   In this case the Employer gave termination letters on April 17, 2014 giving them working notice ending March 27, 2015 , some 11 months. However all that working notice was useless as the Employer did not file the Form 1 until May 12, 2015.