Displaying date/time using the user timezone in ASP.NET MVC

This post will show you how you can display date/time using the user timezone (without it being configured anywhere in your application).

Storing Dates in your Data Source

The first thing you have to do is to make sure that all dates are stored using Universal Cordinated Time (UTC).

The easiest way to do that is to convert it like this:

var dbDate = myDate.ToUniversalTime();

When loading dates, simply do no conversion at all.

Displaying the date/time

The date/time cannot be formatted server-side since the HTTP request contains no information about the time zone. Instead, we have to do it client side (or start using AJAX to configure server side).

Hence, we need to push the date to the client in a way that would allow us to reformat it. The easiest way to do that is to create a display template. The great thing with that is that all date/times will automatically be reformatted if you are using Html.DisplayFor.

Create a template named /Views/Shared/DisplayTemplates/DateTime.cshtml with the following content:

@model DateTime
<span data-date="@Model.Subtract(new DateTime(1970, 1, 1)).TotalMilliseconds">@Model.ToString()</span>

We simply display the date as UTC. But we do also include the unix date in an attribute. We’ll use that to do the formatting.

Formatting the date/time

Now we only have the formatting left. For that, we’ll use a combination of standard JavaScript and jQuery.

Add this somewhere in your application:

<script type="text/javascript">
$(function(){
    $('[data-date]', container).each(function () {
        // the date construct will automatically convert to local time
        var localDate = new Date(parseInt($(this).attr('data-date')));

        //display time only for today, otherwise only the date.
        // feel free to use your own logic
        var now = new Date();
        if (localDate.getDate() == now.getDate() && localDate.getFullYear() == now.getFullYear() 
                                                 && now.getMonth() == localDate.getMonth()) {
            $(this).html(localDate.toLocaleTimeString());
        } else {
            $(this).html(localDate.toLocaleDateString());
        }
    });
});
</script>

End Result

Done.

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