T1 tax returns and T1135 filing for 2018 will start from Monday, February 18, 2019, at 8:30 a.m. (Eastern Time). Any prior year filing (i.e., for 2015, 2016, 2017) including T1 Amendments must be completed before 11:59 p.m. local time on Friday, January 25, 2019. During this period CRA’s EFILE and ReFILE services will stop transmission of return in order to convert its system to prepare for the next filing season.