You need to follow the date format YYYYMMDD in the URL regardless of the date format in the Airtable.

If the date field includes a time component, and you wish to prefill both the date and time, simply append a plus sign followed by the time in the 24-hour format. The prefill format should now follow this pattern: YYYYMMDD+HHMM (e.g., 20240101+1300).