Blazor InputDate Control Display Problem when the Bound Date is Empty

Here is the markup:

<InputDate @bind-Value="@EndTime" Type="InputDateType.DateTimeLocal" bind-Value:format="@DateTimeFormat" style="width:250px" />

The DateTimeFormat = "dd/MM/yyyy HH:mm".

When the control is displayed on the page while EndTime is null, it displays "mm/dd/yyyy --:-- --" as a placeholder. I want the control to be empty when the bound value is null. How can I achieve this? There isn't a placeholder property on the control.

Another bugaboo is that the "AM/PM" is used even though the format calls for a 24 hour time.

It's default behaviour of <input type="date"/> and you will need to override the built-in css of input which is hard to achieve.
You could try a workaround to make it transparent when value is null.

<style>
    .null-date {
        width: 250px;
        color: transparent; 
    }
    .non-null-date {
        width: 250px;
        color: black; 
    }   
</style>


<InputDate id="input3" @bind-Value="@EndTime" Type="InputDateType.DateTimeLocal" class="@((EndTime!=null)||(Focus) ?"non-null-date":"null-date")" @onfocus="()=>{Focus=true;}" @onfocusout="()=>{Focus=false;}" />

@code{
    private DateTime? EndTime { get; set; } = null;

    private bool Focus = false;
}