A delivery date answers "which day." A time slot answers "when that day" — and for a lot of merchants, that's the difference between an efficient delivery route and a wasted one. This guide shows how to offer delivery time windows on Shopify, cap each one, and enforce the choice at checkout — with no code.
Why time slots, not just dates
Same-day and local-delivery merchants live and die by routing. If everyone picks "Saturday," you still don't know when to send the van. Time windows — 10:00–12:00, 14:00–16:00, 18:00–20:00 — let customers self-select into the capacity you actually have, and they match the fixed windows Japanese carriers already use.
Delivery slot, delivery window, date picker — which is which?
These get used interchangeably and they aren't the same thing.
| Term | What it is |
|---|---|
| Delivery date picker | The calendar the customer chooses a date from |
| Delivery slot | A bookable time band on a date — 14:00-16:00 — with its own capacity |
| Delivery window | The range you show as an estimate — "arrives 10-11 July" |
| Shipping date picker | Loose wording for the same calendar, though shipping date properly means the day it leaves you |
The distinction that matters operationally: a window is a prediction you make, a slot is a commitment the customer books. Slots carry capacity, so ten bookings in a 14:00-16:00 slot is ten deliveries you have promised for that band. Windows carry no capacity at all.
How it works in OrderRules
On the Advanced plan, you build time slots as a template and attach it to any availability rule:
- Define your windows. Add the slots you offer; they appear under the chosen date on the storefront picker.
- Cap each window. Give a slot its own Cap/day so it can sell out independently of the date. See delivery capacity limits.
- Live sell-out. Full slots grey out automatically — customers only see what you can fulfill.
- Checkout enforcement. The OrderRules Shopify Function blocks a sold-out or invalid slot, even on Shop Pay and express checkouts.
Slots that map to your carrier
Load a carrier preset — Yamato, Sagawa, or Japan Post — and your windows match that carrier's time bands. At export, OrderRules maps each slot to the carrier's native slot code automatically. A custom window that doesn't match one of the carrier's bands exports without a slot code, so stick to the carrier's bands if you ship with them. See Carrier CSV export.
Set it up
- In Delivery, open Time slot templates. Load a carrier preset or add your own windows.
- Give each window a Cap/day if you want it to sell out. Leave it blank for unlimited.
- Edit an availability rule and pick the template under Time slot template.
- Save. Slots render under each date; checkout enforces them.
Full detail: Time slots. For the complete flow, start with How to add a delivery date picker to Shopify. Offering collection instead of delivery? Time-window capacity works the same for in-store & local pickup. Not sure where the picker itself belongs? See product page, cart, or checkout.
See the Delivery Dates feature or start a free 14-day trial.