Use the current permission and actual process, not merely a previous employer relationship or historic dates.
Update the start sequence
Review the new offer and relevant status history. A familiar job does not authorize work before the required current permission exists.
Work backward from the last fact that could change the classification: finalized duties, a required credential record, the employer letter, or a changed client assignment. Employers should be told honestly what the realistic earliest start date is, because a date promised on the basis of the immigration step alone will not survive contact with the licensing process. The admission or petition decision is made at the time of the actual request, and a weather- or season-dependent business deadline does not shorten or bypass that process. The period granted relates to the employment described in the employer's letter, and the officer decides the admission period; it is not set by the applicant's preferred schedule. Once admitted, record the TN expiry and the licence and certification expiries side by side; the renewal sequence should begin several months before the earliest of them so the second entry does not repeat the first delay. The safer sequence keeps the Canadian licence current and the Canadian job in place until the state credential issues, then moves quickly, because the immigration step itself is measured in a day.