The date the qualifying year abroad is complete, how quickly the foreign affiliate can produce employment records, and how long managers take to describe the knowledge in usable detail. A corporate restructuring or an unsettled worksite plan can add further review before anything can sensibly be filed.
Work backwards from the assignment date
Set milestones for the ownership evidence, the employment records and the knowledge description, then review the package as a whole before deciding on a filing date. Keep the business start date flexible until the assessment is finished. Petition approval, a visa where one is required, admission, and the point at which work may lawfully begin are separate stages, and planning should treat them that way.
Hypothetical example: a specialist in the organisation's ticketing and access-control platform is expected on site for a deployment window ten weeks away, and the knowledge description is scheduled to be written last. A first review would reverse that order, because the description depends on manager time rather than on external records and is therefore the element most likely to slip quietly. It would set a date for each of the four elements, review the package as a whole once, and give the receiving office an honest date rather than the one the deployment plan assumed.