After the year is complete, not before. The requirement is one continuous year of qualifying employment abroad within the three years preceding the petition, so filing early on the strength of a fourteen-month association that includes contract months puts the case at risk over a point that four months of patience resolves.
Use the waiting period to build the file
Four months is enough to do everything else properly. Assemble the ownership documents, prepare the American organizational chart, obtain trading evidence for both companies, and write the description of the managerial role while the person is still performing the Canadian one. Talk to the subsidiary about what it needs before the transfer and whether an interim arrangement is possible that does not involve the manager working in the United States. Confirm from payroll the exact date the qualifying year completes and diarise it. Then file with a complete record on a date nobody has to explain, which is a far better position than filing in month eleven and spending the following six answering questions about invoices.
Hypothetical example: a Tyendinaga book distributor wants its regional manager in the United States before a major catalogue launch. Start with the foreign employment dates and confirm that one qualifying year fits within the relevant three-year lookback. Then allow time to collect corporate records and describe the U.S. managerial role. A calendar that begins with the launch date, rather than the evidence, often discovers the gap only after commitments have been made. It is safer to move the launch milestone than to submit an incomplete history that leaves the qualifying period uncertain.