Hi, David,

Thanks a lot for the submitted feature request - we will monitor the interest in it closely!

Currently, there is no built-in configuration in toODataString to output date-only strings for Edm.Date fields. The toODataString method from @progress/kendo-data-query always serializes JavaScript Date objects as full date-time strings (e.g., "YYYY-MM-DDT00:00:00.000Z"), even when the target field in OData is of type Edm.Date, which expects a date-only value ("YYYY-MM-DD").

To generate a date-only value, you can try to manually format your filter value before passing it to toODataString in a similar way:

const dateToEdmDate = (date) => date.toISOString().slice(0, 10);

const filter = {
  logic: 'and',
  filters: [
    {
      field: 'FirstOrderedOn',
      operator: 'eq',
      value: dateToEdmDate(selectedDate), // selectedDate is a JS Date object
    },
  ],
};

const odataString = toODataString(filter);

Kind Regards,
Vessy
Progress Telerik