Income Tax Act: Determination of date upon which employer’s return (EMP 501) must be rendered (Gazette 39922, Notice R436) 
https://newsletter.po.creamermedia.com/article/income-tax-act-determination-of-date-upon-which-employers-return-emp-501-must-be-rendered-gazette-39922-notice-r436-2016-04-25
25th April 2016
Income Tax Act: Determination of date upon which employer’s return (EMP 501) must be rendered (Gazette 39922, Notice R436)