Seasonal demand often begins before the service itself is needed. Someone who wants to use a terrace in spring may start researching designs and materials in winter. A content calendar should account for that lead time.
Begin with your own enquiries
For the periods you have available, collect the dates of first enquiries, quotations and completed work. These represent different stages. Also note whether a particular promotion, weather event or business interruption may have influenced the pattern.
For a small number of enquiries, a simple monthly overview is sufficient. Do not immediately interpret an isolated spike as an annual pattern. One large September project does not prove that September is always the most important month for attracting customers.
Add search trends as another perspective
Google Trends can suggest recurring interest. However, its figures are relative values rather than absolute search volumes, as the Trends data documentation explains. Compare the same region and period, and do not automatically read a zero as an absence of demand.
Investigate several plausible terms. Customers may search for a problem before knowing the name of its solution. For a gardening business, spring maintenance questions might appear before searches for a specific appointment.
Work backward from the customer's decision
First mark when customers need to make a decision. Research, internal discussion, a quotation and possibly delivery time come before that date. A useful information page should not be created only on the day seasonal interest peaks.
Separate lasting explanations from changing details. The consultation process may stay the same, while dates, available services and deadlines need checking. This avoids publishing an almost identical new page every year.
Reserve time for the period after the season too. Remove expired offers, explain the next available appointment if relevant, and record questions that appeared unusually often. Those notes will improve the next plan more than simply copying last year's calendar.
A seasonal plan remains an informed assumption. Set a review date before the anticipated rise in demand. If supply capacity or customer questions have changed, adjust the calendar rather than treating the original dates as fixed commitments. The point is to have the right information available when decisions begin, not merely to publish something during the busiest week.
