Short answer
Your written quotation confirms the delivery schedule for this wedding suits commission, including cloth, production and destination. London's proposed visit window is DEC; dates and venues are confirmed individually.
Share the wedding date when you enquire. Your written quotation confirms whether the cloth, production and delivery schedule is feasible before you order.
London's window
The proposed DEC visit is the planning point for London 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.