This year's deadline to file your personal income tax return is midnight on May 5 – five days later than the usual Apr. 30 cutoff. You can thank that nasty Heartbleed computer bug for the extension, after it forced the Canada Revenue Agency to shut down its E-File system earlier in April.his year's deadline to file your personal income tax return is midnight on May 5 – five days later than the usual Apr. 30 cutoff. You can thank that nasty Heartbleed computer bug for the extension, after it forced the Canada Revenue Agency to shut down its E-File system earlier in April.