Special Dates in Blazor DatePicker Component

12 Dec 20254 minutes to read

You can customize specific dates in a DatePicker by using the OnRenderDayCell event. This event gets triggered on each day cell element creation that allows you to customize or disable the specific dates in the DatePicker. Here, list of dates in the current month are customized with custom styles by adding the personal-appointment and official-appointment class.

@using Syncfusion.Blazor.Calendars
<div class="control-wrapper">
    <SfDatePicker TValue="DateTime?" Placeholder="Choose a Date" ShowClearButton="true" @bind-Value="@SelectedDate">
        <DatePickerEvents TValue="DateTime?" OnRenderDayCell="CustomDates" ValueChange="OnChange"></DatePickerEvents>
    </SfDatePicker>
</div>
<div id="display-date">
    <span>Selected Day : @SelectedValue</span>
</div>
@code {
    public DateTime? SelectedDate { get; set; }
    public string SelectedValue { get; set; } = DateTime.Now.ToString("M/d/yyyy");
    public DateTime? CurrentDate { get; set; } = DateTime.Now;
    public void CustomDates(RenderDayCellEventArgs args)
    {
        if (args.CurrentView == "Month") {
            var CurrentMonth = CurrentDate.Value.Month;
            if (args.Date.Month == CurrentMonth && (args.Date.Day == 7 || args.Date.Day == 14 || args.Date.Day == 24 || args.Date.Day == 29)) {
                args.CellData.ClassList += " personal-appointment";
            }
            if (args.Date.Month == CurrentMonth && (args.Date.Day == 3 || args.Date.Day == 11 || args.Date.Day == 17 || args.Date.Day == 22))
            {
                args.CellData.ClassList += " official-appointment";
            }
        }
    }
    public void OnChange(ChangedEventArgs<DateTime?> args)
    {
        var Count = 0;
        var CurrentMonth = CurrentDate.Value.Month;
        if (args.Value.Value.Month == CurrentMonth && (args.Value.Value.Day == 7 || args.Value.Value.Day == 14 || args.Value.Value.Day == 24 || args.Value.Value.Day == 29))
        {
            this.SelectedValue = this.SelectedDate?.ToString("M/d/yyyy") + " (Personal appointment)";
            Count++;
        }
        if (args.Value.Value.Month == CurrentMonth && (args.Value.Value.Day == 3 || args.Value.Value.Day == 11 || args.Value.Value.Day == 17 || args.Value.Value.Day == 22))
        {
            this.SelectedValue = this.SelectedDate?.ToString("M/d/yyyy") + " (Official appointment)";
            Count++;
        }
        if (Count == 0)
        {
            this.SelectedValue = this.SelectedDate?.ToString("M/d/yyyy");
        }
    }
}
<style>
    #display-date {
        max-width: 270px;
        padding: 15px 0;
        font-size: 13px;
    }
    .control-wrapper {
        width: 300px;
        margin: 0 auto;
        padding-top: 50px;
    }
    .e-calendar .e-content .e-cell.personal-appointment span.e-day,
    .e-calendar .e-content td:hover.e-cell.personal-appointment span.e-day,
    .e-calendar .e-content td.e-selected.e-focused-date.e-cell.personal-appointment span.e-day {
        color: #28a745;
        font-weight: 800;
    }
    .e-calendar .e-content .e-cell.official-appointment span.e-day,
    .e-calendar .e-content td:hover.e-cell.official-appointment span.e-day,
    .e-calendar .e-content td.e-selected.e-focused-date.e-cell.official-appointment span.e-day {
        color: #dc3545;
        font-weight: 800;
    }
    .e-calendar .e-content td.e-selected.e-focused-date.e-cell.personal-appointment span.e-day,
    .e-calendar .e-content td.e-selected.e-focused-date.e-cell.official-appointment span.e-day {
        background-color: #b511485e;
    }
</style>

NOTE

The RenderDayCellEventArgs includes a CurrentView property that identifies the active calendar view during rendering. Possible values are Month, Year, and Decade. Use this to apply view-specific logic within the OnRenderDayCell handler. This property is useful for customizing the rendering of day cells based on the calendar’s current view.