Define the actual window
State the earliest and latest acceptable receiving dates, expected holding period and intended dispatch date. If those dates depend on a vessel or a purchase agreement, identify the dependency rather than giving a single unqualified date.
Compare the full commitment
A short holding period does not necessarily produce a short billing commitment. Ask about minimum terms, minimum capacity, handling costs, extensions and the conditions for releasing product.
Keep alternatives visible
If your preferred timing is unavailable, consider whether a different window, parcel size or terminal access arrangement is practical. Changes should be assessed against the cargo and contract, not assumed to be interchangeable.