Odata filter on date

Hello, I want to filter on a date and I can not get it to work. I want to add the birthday code at the top in the the var statement so it will not give me the can not load data error.

//and 'Birthday eq 1992-03-23T00:00:00.000Z'

            var result = await MHMService.GetClients(filter: $@"(contains(LastName,""{search}"") or contains(FirstName,""{search}""))

and {(string.IsNullOrEmpty(args.Filter) ? "true" : args.Filter)}",
orderby: $"{args.OrderBy}", top: args.Top, skip: args.Skip, count: args.Top != null && args.Skip != null);

Can anyone please explain this?

On our demo for OData binding there is no problem to filter by date: