Delta agriculture sets the calendar
Building here follows the paddy cycle, concentrating demand into the weeks after the crop is sold. The pre-season order is made once and cannot be corrected mid-season, so last year's movement over the same weeks is the only honest basis for it.
Temple and heritage construction
Restoration and temple-linked building brings buyers who work through trusts and committees, paying against documents on their own timetable. Those accounts are long-term and steady, and they want a referenced invoice and a delivery record that reconciles.
Deliveries across the delta
The delta's roads are indirect and a delivery may take longer than the distance suggests. Vehicle, date, destination and receiver on the challan, held against the party, is what settles a question weeks later without either side relying on memory.