Raise the actual history during initial planning, before commitments depend on an assumed qualifying date. Identify missing records and the proposed U.S. duties. A customer go-live date and a qualifying period run on separate clocks, and only one of them can be renegotiated. Commercial schedules move when the parties agree to move them; the three-year window is measured backwards from the request and shifts whether or not anybody is ready for it.
Plan from a reviewed chronology
Have the applicable employment period and current knowledge assessed together but distinctly. Do not count or exclude time automatically, and do not assume a return-to-work announcement answers the immigration timing question. Two limits belong on the same page as the project plan.
Stay in L-1B is generally capped at five years, and time already spent in the United States in L status counts toward that maximum, so an assignment planned as the first of several should be mapped across the whole sequence rather than one posting at a time. The qualifying year abroad sits at a fixed point in the past, meanwhile, and drifts toward the edge of the three-year window with every month of delay. Where an absence has already consumed part of that window, have the year located precisely before a start date is promised to a customer or a colleague.