The record should accurately explain the proposed employment and any difference between the agreements. Do not select a date solely because it appears to allow a longer stay. The appropriate requested period and supporting explanation depend on the actual arrangement and procedure.
Reconcile the documents before submission
Identify whether the applicant will perform other qualifying work for the same employer after this project and what is genuinely proposed. Keep contingent assignments clearly marked. A coherent explanation is more useful than making every document display an identical date without factual support.
Build the file so that every element has one document that carries it, and no document is asked to carry two. Citizenship is proved by a Canadian or Mexican passport or citizenship certificate — never by a permanent resident card. The listed profession is proved by the employer’s support letter, which should name the appendix occupation, describe the duties in plain terms, state the remuneration, give the period of the engagement and identify who supervises the work. The credential is proved by the diploma or degree itself, with a foreign-credential evaluation where the qualification was earned outside North America, plus the state licence when the appendix entry demands one. Where the appendix accepts experience instead of a degree, it is employer letters setting out dates, hours and duties that carry the alternative, not a résumé.
One element needs paper of its own: the arrangement must not be disguised self-employment. If the applicant holds shares in the hiring company, the file should say so and show who directs the work and who could dismiss the applicant.
Hypothetical example: a marine acoustics analyst is engaged through a consultancy for a shipyard programme. Two letters are needed — the consultancy’s, establishing the employment relationship, and the client’s, confirming the work to be performed — and both must describe the same duties.
Label each exhibit with the element it proves. An officer reading a tabbed file at a port of entry or preclearance has minutes, and the same exhibits are what an employer’s Form I-129 filing with USCIS would rest on.