When do parcel queues form, and how early should you ship?

Parcel flow is seasonal in a way that is easy to forget: a warehouse holiday in one country becomes a two-week delay in another.

The calendar marks the months when dispatch and flights tighten, gives a reason for each, and converts that into a lead time you can plan against.

A month marked high does not predict a late parcel; it describes congestion on the dispatch side. The destination selector adds a note about arrival handling and changes nothing else, so the level and the lead time are read from the month alone and the same figure is quoted for every route. That is deliberate, since closure dates in China are shared, but it means route-specific delay has to be allowed for separately. Read the destination note as its own allowance rather than as a modifier of the level.

Lead time here is expressed relative to your usual schedule, which makes it a top-up rather than a date. If orders normally go out ten days before a deadline, a high month asks for seventeen to twenty; a plan that already carried a fortnight of buffer would count the same risk twice. The unit is also coarse: a month is one row, and cut-offs move inside it. Confirm the exact closure date with the warehouse in writing. Published holiday calendars are not verified here, and closure lengths vary by year.