Hello,

A Date/Time Picker is bound to a nullable DateTime value. If the user clears the value with the keyboard, the component will show as invalid (with red border). Instead, the picker should treat null values as valid.

Here is a test page with a few different workarounds:

<TelerikButton OnClick="@( () => DateValue = null )">Clear Value</TelerikButton>
<TelerikButton OnClick="@( () => DateValue = DateTime.Now )">Set Value</TelerikButton>

DateValue.HasValue: @DateValue.HasValue

<p>Default behavior:</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px" />

<p>Red border will disappear after blur (CSS):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   Class="@( !DateValue.HasValue ? "valid-null" : "" )" />

<p>Red border will never appear (CSS):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   Class="valid-null" />

<p>Red border will disappear after blur (OnChange):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   OnChange="@OnPickerChange" />


<style>
    .k-input.k-invalid.valid-null {
        border-color: rgba(0, 0, 0, 0.08);
    }
</style>

@code {
    private DateTime? DateValue { get; set; } = DateTime.Now;

    private async Task OnPickerChange(object newValue)
    {
        DateTime? newDate = (DateTime?)newValue;

        if (!newDate.HasValue)
        {
            DateValue = DateTime.Now;
            await Task.Delay(1);
            DateValue = null;
        }
    }
}

Is there any way to display the DateTimePicker and for the time picker to display time intervals of less than one second?  For example every 15 minutes?

Select a time:

15:00

15:15

15:30

15:45

etc?

With Blazor server, clicking the NOW button (obviously) sets the time to the time on the server since that's where the code is running. Is there a way to trap the NOW button click or somehow give it an offset or define the value that NOW means so NOW will mean the time that the user is sitting in?

---

ADMIN EDIT

One way this could land could be through templates for the header areas of the calendars - that would let you put your own NOW button there so you can handle its click and change the value as desired. So, you may want to follow and/or Vote for this approach here: https://feedback.telerik.com/blazor/1468855-header-template-for-the-calendars.

A workaround for the time being could be hiding the Now button with some CSS:

<style>
    .no-now-button .k-time-now {
        display: none;
    }
</style>

Selected time: @selectedTime
<br />

<TelerikDateTimePicker PopupClass="no-now-button"
                       Min="@Min" Max="@Max" @bind-Value="@selectedTime"
                       Format="dd MMM yyyy HH:mm:ss" Width="250px"></TelerikDateTimePicker>

@code {
    private DateTime? selectedTime = DateTime.Now;
    public DateTime Min = new DateTime(1990, 1, 1, 8, 15, 0);
    public DateTime Max = new DateTime(2025, 1, 1, 19, 30, 45);
}

---

Add "OnOpen" event that fires when the DateTimePicker  button is clicked but before the DateTimePicker  dropdown is shown

=============

ADMIN EDIT

=============

You can currently achieve the desired behavior by wrapping the DateTimePicker in a container (for example span), add a handler on the on-click event of the span to catch the click event and perform the desired actions in that handler.

<span class="datetimepicker-span" @onclick="@OnOpenHandler">
    <TelerikDateTimePicker Class="my-date-time-picker" Value="@selectedTime"
                           Format="dd MMM yyyy HH:mm:ss" Width="250px"></TelerikDateTimePicker>
</span>

@code {
    public DateTime? selectedTime { get; set; }

    public bool isOpened { get; set; } = false;

    public void  OnOpenHandler()
    {
        isOpened = !isOpened;

        if (isOpened)
        {
            Console.WriteLine("DateTimePicker was opened.");
        }
        else
        {
            Console.WriteLine("DateTimePicker was closed.");
        }
    }
}

If you enter a format with a 24 hour time( Format="dd MMM yyyy HH:mm:ss")  for the Timepicker

If you enter the same format for the DateTimePicker the TimePicker in the DateTimePicker looks like this:

It seems like this is a bug as the only way I can change the DateTimePicker time UI is to alter my language/culture whereas the TimePicker displays correctly based on my format. 

Hi.

When entering an invalid date in a DateTimePicker, the component will automatically revert the entered value back to its previous valid value.

I didn't expect this because the user may type in an invalid date, and continue to the next input control within the form, and not notice the error that was briefly displayed.

The issue can be reproduced in the DateTimePicker Demo here: https://demos.telerik.com/blazor-ui/datetimepicker/validation

Steps to reproduce:

1. Click in the day part of the date.

2. Enter 13

3. Enter 2100

4. Press the Tab key

5. Notice the date is automatically reverted (back) to 10/13/2019.

I expected the date to be set to 10/13/2100 with the input validation errors visible to the user after pressing the Tab key in step 4.

I've categorized this issue as a bug because otherwise, the form can be submitted with a value that the user did not enter.

If this behavior cannot be changed from being the default behavior, then there should be an option to prevent this behavior from happening.

Thank you.

Hey Telerik team,

We encountered issue with DateTime picker which I was able to reproduce in your Documentation preview.

If you hover over the date time dropdown, but really slowly it bugs out and the view becomes unusable like this:

As you can see, the dropdown is messed up and it seems like the hover over the border is trying to trigger some action to change from date to time pick automatically

Jakub

I'd like to have the ability to disable dates and times.

DateTimePicker loses focus when the NOW button is clicked. 

To reproduce the problem open the following demo:

https://demos.telerik.com/blazor-ui/datetimepicker/overview

Try clicking a few times on the NOW button. The focus is occasionally lost. 

https://www.screencast.com/t/BPEXTy43

If you are zooming a page containing a DateTimePicker with "AdaptiveMode" set to "AdaptiveMode.Auto", the application crashes occasionally with the error:

Microsoft.JSInterop.JSException: Cannot read properties of null (reading 'addEventListener')
TypeError: Cannot read properties of null (reading 'addEventListener')

The more adaptive DateTimePicker instances the page contains, the more likely the error is to occur.

I want to set the initially focused time/date for the DateTimePicker before opening the picker to improve the user experience. When opening the DateTimePicker with a null value the preselected date is the current day and the time is always 00:00/12:00AM.

I do not want to set value for the component but rather alter the time/date that will be initially focused when opening the popup.

===

ADMIN EDIT

===

The request also applies to the rest of the pickers - DatePicker, DateRangePicker and TimePicker.

I want the user to only be able to select times between, for example, 11AM and 1PM. Setting Min and Max does not limit that, I can select any time:

Based on the example https://demos.telerik.com/blazor-ui/datetimepicker/overview, on Cancel or Set, the Input gets focused. On the mobile, it causes the keyboard to appear as well, which is not an intuitive behaviour.

Is it possible for this behaviour to be removed?

---

ADMIN EDIT

This behavior is OS specific, in our tests iOS does not exhibit it. It is generally up to the OS to show the soft keyboard and the web app should not be able to alter that.

Also, generally speaking from an accessibility point of view, popups must have a default focus (we do that), and when they close, they must return the user to the flow of the application in the place where they took it from. In this case, that's an interaction with the picker component.

Nevertheless, if the focus went to the button rather than the input, it is highly likely that the behavior would be resolved. The only downside would be that Android users will need a second action to get the focus back in the input.

---

Hi,

I have a REPL showing the issue.

I am using DataAnnotation where possible in my application and I was expecting the DisplayFormat attribute to be applied in the DateTimePicker like it is for DatePicker but as shown in the REPL link below it's not. I will use a workaround of applying the Format attribute everywhere but I would appreciate this being changed.

https://blazorrepl.telerik.com/GdkpcclE28sZ9VZH54

 I want to to be able to catch the click of the Set button regardless of whether or not the value was changed.

==========

ADMIN EDIT

==========

For the time being, a possible workaround could be to use some JS Interop to catch the click of the Set button. You can create a custom OnOpen event for the DateTimePicker dropdown as per the admin edit example in this post. You can use the OnOpenHandler to invoke the JS responsible for catching the click event of the Set button. The example below demonstrates the described approach.

@inject IJSRuntime JSInterop

Selected time: @selectedTime
<br />
<span class="datetimepicker-span" @onclick="@OnOpenHandler">
    <TelerikDateTimePicker Min="@Min" Max="@Max" @bind-Value="@selectedTime"
                           Format="dd MMM yyyy HH:mm:ss" Width="250px">       
    </TelerikDateTimePicker>
</span>

@code {

    public bool isOpened { get; set; } = false;

    public async Task OnOpenHandler()
    {
        isOpened = !isOpened;

        if (isOpened)
        {            
            await JSInterop.InvokeVoidAsync("SetBtnClicked", ".k-time-accept");

            isOpened = false;
        }        
    }    

    private DateTime? selectedTime = DateTime.Now;
    public DateTime Min = new DateTime(1990, 1, 1, 8, 15, 0);
    public DateTime Max = new DateTime(2025, 1, 1, 19, 30, 45);

}

    <script>
        function SetBtnClicked(selector) {
            var element = document.querySelector(selector);
            element.addEventListener('click', function () {
                alert("Set button clicked");
            });
        }
    </script>

I can't type AM or PM in the DateTimePicker to explicitly change to AM or PM.

For example:

1. Go to https://demos.telerik.com/blazor-ui/datetimepicker/overview.

2. Click on AM or PM in the DateTimePicker field.

3. Try to type "AM" or "PM".

4. If the time is "AM", notice that typing "PM" does not change "AM" to "PM", and visa-versa.

This causes our UI tests to fail when entering a date that has a different meridian time than the current time.

I expected the same behavior as the UI for ASP.NET Core: https://demos.telerik.com/aspnet-core/datetimepicker.

----------ADMIN EDIT----------

In the meantime, you can achieve the desired functionality by following the steps from the knowledge base article below.

Select AM/PM by pressing A or P on the keyboard - KB