This is a continuation of public item DatePicker, TimePicker and DateTimePicker should accept null value as valid when bound to nullable DateTime

The problem persist when:

• The component Format includes a week day.
• The component Format is set with a standard date format string (d, D, g, etc.)

Test page with workarounds:

Bug due to week day format string inconsistency between .NET and JavaScript (dddd vs EEEE):

<TelerikDateTimePicker @bind-Value="@SelectedTime"
                       ShowClearButton="true"
                       Width="360px">
    <DateTimePickerFormatPlaceholder Weekday="week" />
</TelerikDateTimePicker>

<br />
<br />

Bug due to usage of a standard date format string:

<TelerikDatePicker @bind-Value="@SelectedTime"
                   ShowClearButton="true"
                   Format="d"
                   Width="360px">
    <DateTimePickerFormatPlaceholder Day="dd" Month="mm" Year="yyyy" />
</TelerikDatePicker>

@code {
    private DateTime? SelectedTime = DateTime.Now;
}

The DateInput rendering performance worsened in version 4.6.0 and the component renders more slowly. This is easily visible when there are multiple DateInputs on the page:

4.5.0: https://blazorrepl.telerik.com/mdPFuXFI02i7Ulbo52

4.6.0: https://blazorrepl.telerik.com/GdlbEXPe00IhfKWN29

When you check and uncheck the checkbox, the DateInputs appear more slowly with version 4.6.0.

There is also a Grid, which is commented out. If you show it, the virtual scrolling will exhibit a temporary freeze before rendering of the new rows - the user sees the loading skeletons for a second even after they have stopped scrolling.

The DateInput / TimePicker display the current Format instead of the component Value when the current culture / localization is not English (en).

DateTime values show as expected.

When AutoCorrectParts is false and you type a date starting with 0, the caret will immediately move to the next DateTime format segment, before the user has typed the second date digit.

Test page: https://blazorrepl.telerik.com/cfOcaAbv48WGOUM530

<p><strong>Type 05 in the day segment:</strong></p>

@DateInputValue?.ToString("dd/MM/yyyy")
<br />
<TelerikDateInput @bind-Value="@DateInputValue"
                  Format="dd/MM/yyyy"
                  AutoCorrectParts="false" />

@code {
    private DateTime? DateInputValue { get; set; } = new DateTime(2025, 2, 6);
}

When the DateInput value is in February, AllowCaretMode is true and you type a date of 30 or 31, the caret will jump to the end of the textbox content, after the year segment.

Here is a test page: https://blazorrepl.telerik.com/cpkmugvl11AMdpgn21

<TelerikDateInput @bind-Value="@DateInputValue"
                             Format="dd/MM/yyyy"
                             AutoCorrectParts="false"
                             AutoSwitchParts="true"
                             AllowCaretMode="true"
                             Width="200px" />

Used a MacBook Pro for this test.

• Used the Telerik UI for Blazor Productivity Tools extension in VS Code
• Launch - Telerik UI for Blazor Template Wizard
  • template - dashboard
  • telerik version 5.1.1
  • enable localization
  • .net 7.0
• Create a razor file with the TelerikDatePicker component and a binded value attribute for selected date
  • The selected date variable should be set to a default DateTime value
    • I used new DateTime(2024,9,1)
  • The attribute Format is not used in the component
  • Below the component show the value for the System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern variable

• Comment out all TileLayoutItems from Tile Layout
• Add DatePicker component to a TileLayoutItem
• In your terminal run dotnet watch to run the app
  • English is the culture in the top right
  • The format of the default date in the datepicker should be MM/dd/yyyy
    • Date is 9/1/2024
    • ShortDatePattern is M/d/yyyy
  • Switch the culture to German
  • The format of the date value should be dd.MM.yyyy
    • Date is 9.1.2024
    • ShortDatePattern is dd.MM.yyyy

The Min and Max parameters of the DateInput, DatePicker and TimePicker don't work if the component Value is of type DateOnly or TimeOnly. Here is a test page:

<p>
    Allowed dates between @DateInputMin.ToShortDateString() and @DateInputMax.ToShortDateString(). Enter an invalid date:
</p>

Nullable DateTime (if out of range, will <strong style="color:green">nullify</strong>):
<TelerikDateInput @bind-Value="@NullableDateTimeValue"
                  Min="@DateInputMin"
                  Max="@DateInputMax"
                  Width="120px" />

@NullableDateTimeValue?.ToShortDateString()

<br />
<br />

DateTime (if out of range, will <strong style="color:green">autocorrect</strong>):
<TelerikDateInput @bind-Value="@DateTimeValue"
                  Min="@DateInputMin"
                  Max="@DateInputMax"
                  Width="120px" />

@DateTimeValue.ToShortDateString()

<br />
<br />

Nullable DateOnly (if out of range, will <strong style="color:red">accept</strong>):
<TelerikDateInput @bind-Value="@NullableDateOnlyValue"
                  Min="@DateInputMin"
                  Max="@DateInputMax"
                  Width="120px" />

@NullableDateOnlyValue?.ToShortDateString()

<br />
<br />

DateOnly (if out of range, will <strong style="color:red">accept</strong>):
<TelerikDateInput @bind-Value="@DateOnlyValue"
                  Min="@DateInputMin"
                  Max="@DateInputMax"
                  Width="120px" />

@DateOnlyValue.ToShortDateString()

@code {
    private DateTime DateTimeValue { get; set; } = DateTime.Today;
    private DateOnly DateOnlyValue { get; set; } = DateOnly.FromDateTime(DateTime.Today);

    private DateTime? NullableDateTimeValue { get; set; } = DateTime.Today;
    private DateOnly? NullableDateOnlyValue { get; set; } = DateOnly.FromDateTime(DateTime.Today);

    private DateTime DateInputMin { get; set; } = DateTime.Today.AddYears(-10);
    private DateTime DateInputMax { get; set; } = DateTime.Today;
}

The input should be focused after the user clicks the clear button.

Reproduceable example: https://blazorrepl.telerik.com/wSEgunbK46sVmd1p02

In my use case, I have custom components that wrap each of the telerik date controls (date picker, time picker, etc). They each expose a SelectedDate/SelectedTime/etc. bindable property. The SelectedDate is populated when the telerik control in my component (like TelerikDatePicker) fires OnChange. I use this instead of ValueChanged to avoid too many UI updates while the user selects a value in the UI, such as when typing. The OnChange event fires when the date input loses focus, but if the date input didn't have focus when the clear button is clicked, it never loses foucs and never fires OnChange. Let me know if this isn't intended to be supported and I should just be using ValueChanged instead, but to me OnChange would imply it would fire in all cases when the value can also change through ValueChanged, just less often.

Steps to reproduce (I used a TelerikDatePicker in the code above but I could reproduce this locally with date time picker and time picker - it's related to the underlying DateInput):

• Enter a date into the date picker, either through typing or using the calendar popup
• Cause the date picker to lose focus by clicking away
• Click the clear button
• Notice that the date is cleared from the UI control, but it doesn't call OnChange, so the date on the page never updates

When I discovered this locally, clicking the clear button would not clear the date visually from the date input as well as not updating the actual date variable. In the REPL, I was not able to replicate this - the date clears visually in the UI.

The DateInput and all related date/time pickers display 1970/1/1 after programmatic Value clearing and subsequent focus.

The behavior was correct until version 4.6.0 inclusive.

<TelerikDateInput @bind-Value="@DatePickerValue"
                  Width="200px">
</TelerikDateInput>

<TelerikButton OnClick="@( () => DatePickerValue = default )">Clear Value</TelerikButton>

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

Hi,

This is easily viewable in your demos.  Using Safari, go to:

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

Try to use keyboard arrows left and right and up/down to change date.  It doesn't hold the selected date part.  

Works fine in Chrome / Firefox.

Using Telerik Blazor 4.0.1.  Previously on 3.5.0, there were no issues.  The only other difference is .NET 7.0.

Create a blank Telerik Blazor Server project and use the attached index.razor.  In the OnInitialized, there are two lines that set the DateTime.  The first one works but the second one results in the TelerikDateInput field showing h:mm AM instead of 12:00 AM.

Am I doing something wrong?  If so, what changed from 3.5 to experience this?

Thanks,

Chuck

My users want to paste dates in the date inputs (date pickers in our case). This seems to work in Kendo, but does not work in Blazor, even when the format of the copied data matches the Format of the component.

<p>
    Try copying this date which is valid in the current format: 23/03/1998
    <br />
    then paste it in the date picker and see what happens to the <code>TheDate</code> field
</p>

@TheDate
<br />

<TelerikDateInput @bind-Value="TheDate" Format="dd/MM/yyyy" /> @TheDate.ToString("dd/MM/yyyy")

@code {
    DateTime TheDate { get; set; } = new DateTime(2019, 11, 27, 02, 03, 44);
}

---

ADMIN EDIT

Allowing the paste into the DateInput (and by extension date picker,...)  would have a lot of cases to control and that is why we have not yet enabled it. If the format is M/d/yyyy, for example, validation for numbers lower or equal to 12 would not be possible when the month is regarded. If the user pastes 8/2/2020 could mean two things - 8th of February 2020 or 2nd of August 2020. This might cause issues as the data that goes to the database might be incorrect and causing the application to misbehave.

That being said, how would you suggest handling the pasting of dates in the component. How would you like from us to handle the format difference of the dates? Please comment below.

---

I would like to be able to configure the auto-tab behavior so that the DateInput only tabs when user type '/' (i.e. disable smart auto-tabbing).

month/day/year 

Expected UX:  3/3/2022
Example: https://demos.telerik.com/kendo-ui/dateinput/index 

Current UX: 332022
Example: https://demos.telerik.com/blazor-ui/dateinput/overview