Short answer
Your written quotation confirms the delivery schedule for this travel wardrobes commission, including cloth, production and destination. Helsinki's proposed visit window is DEC; dates and venues are confirmed individually.
A multi-piece wardrobe can involve more than one city window. The written quotation confirms the scope and delivery schedule before you commit.
Helsinki's window
The proposed DEC visit is the planning point for Helsinki commissions. Dates, venues and available appointments are confirmed individually in writing as the month approaches.
The itinerary is a proposal: months are planned, dates and venues confirmed individually. Final quotations are confirmed in writing before you commit.