Calling JS function automatically when text field is loaded

I have Razor page, where I want to display weekday with translations in index table. I want this calculation to be done and displayed on client side with simple JS function.

Page:

@foreach (var item in Model.Trainings) {
    <tr>
        <td>
            <p call_function?='getWeekday(@item.Since)'></p> <!-- I want weekday to be displayed here -->
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Since)
        </td>
    </tr>
}

JS function:

<script>
        function getWeekday(date) {
            var weekdays = ({
                et: ["Pühapäev", "Esmaspäev", "Teisipäev", "Kolmapäev", "Neljapäev", "Reede", "Laupäev"],
                en: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]
            });

            var d = new Date(date);
            var n = weekdays['et'][d.getDay()]; // currentCultureCode
            return n;
        }
</script>

Is there name or expression how this kind of method is named?