WooCommerce Checkout Blocks can collect a requested delivery date through the Additional Checkout Fields API. A date input is not a booking system: it does not, by itself, reserve driver capacity, enforce holidays or promise an arrival time.
Decide what the date means first
Write the shopper-facing promise before adding the field. "Preferred delivery date" gives operations a request to review. "Guaranteed delivery on this date" commits the store to availability logic and fulfillment capacity. Do not use the stronger label unless the system actually checks those constraints.
For an order-specific request, use the order location rather than saving a recurring preference to the customer's address. The Additional Checkout Fields documentation explains supported locations, registration and the new date type. Date values use YYYY-MM-DD; a calendar date is not a timestamp.
Define a field contract for your developer
| Contract item |
Example requirement |
| Identifier |
handl-delivery/preferred-date |
| Shopper label |
Preferred delivery date |
| Location |
Order information |
| Required |
Only if the fulfillment workflow needs an answer |
| Earliest allowed |
Tomorrow, using a relative date constraint |
| Latest allowed |
Thirty days ahead |
| Downstream field |
requested_delivery_date, kept as a calendar date |
The API supports relative limits such as P1D and P30D. Its documentation advises passing the duration instead of calculating a fixed date during registration. Limits must still be compatible with one another. Avoid mixing a number of days with a number of months without considering short months.
Rehearse the boundary cases
On a staging checkout, try the earliest allowed date, the latest allowed date and one date outside each boundary. Test an omitted value when required. Include a browser left open across midnight and a returning customer who places a second order with a different request.
Your acceptance worksheet should record the selected date, submitted value, saved order value and fulfillment-system value. For a request such as October 20, all four should refer to that same calendar day. A connector that converts it to midnight UTC and displays local time can accidentally move the day backward.
Boundary: Allowed and outside dates tested. Midnight: Open checkout tested across a day. Order: Same requested date persists. Dispatch: No unconfirmed promise. Explanatory checklist, not a customer test result.
Keep availability separate from input formatting
Min and max dates only constrain the range. They do not describe closed days, postal-code coverage, courier cutoff times or how many orders a route can handle. If those requirements matter, use a compatible fulfillment extension or add deliberate server-side availability checks.
Try two shoppers selecting the last available slot in a separate booking test. A field that accepts a date cannot prove that capacity was reserved atomically. For simple requests, make the confirmation explicit: the team will confirm availability separately.
Verify the operational handoff
Complete a guest and signed-in order. Confirm that the date reaches the order view and whatever fulfillment integration staff actually use. Check the confirmation wording with the dispatch team before enabling the field on production.
Use our client/server validation guide for custom validation. HandL WP can connect checkout fields to fulfillment without turning an unconfirmed preference into a misleading delivery promise.
References reviewed October 8, 2026. Examples are explanatory, not customer test results.