The arrival window you promise is a traffic bet, and it decides the booking
Booking rate rises when the window is realistic and falls hard when it is not honored.
A caller in Marietta at 2pm and a caller in Decatur at 2pm are different scheduling problems, even if both are the same distance from your shop. The difference is what sits between the truck and the address at 4pm.
Give the person taking calls a simple zone and time matrix rather than judgment. Which zones can still be promised same day at this hour, which are tomorrow morning, which need a firm two hour window instead of a vague afternoon. A dispatcher who knows the answer books with confidence, and confidence closes.
Track late arrivals as a conversion metric, not a service metric. A window missed by ninety minutes costs the review, the repeat visit and often the replacement job that would have followed.
Where you cannot promise, offer something specific instead: a call thirty minutes ahead, a confirmed morning slot tomorrow, a text when the truck is assigned. Specific beats optimistic.