Hi @PHMG.
Josh from Foxy here. If you end up not getting what you need with Webflow Ecommerce, you might consider integrating Foxy. With our seamless Webflow integration, you can add a date/time picker of your choice to both your add to cart forms and checkout. In addition, you can set specific rules (dependent on the plugin you use).
More info about Foxy + Webflow can be found here. Please don’t hesitate to reach out if you have any questions or need help getting started: hello@foxy.io