I'm a DNN beginner. I am currently building a module in which I can display statistics. My DotNetNuke Version is 7.0. The statistic is from Chartjs. For this statistic I would like to implement filters. These filters should be datepickers. As UI element I have now included a textbox with `TextMode='Date'`. But currently I have problems to set the default value of this field. The default value should be `01.01`. of the current year. 

I have already tried to set the value via C# server side. Unfortunately without success. I also tried to set the value on the client side via JavaScript. Unfortunately also without success.

These are some lines I tried in JavaScript:

document.getElementById(<%= this.DatumVon.AccessKey %>).value = "01.01.2019";
document.getElementById(<%= this.DatumVon.AccessKey %>).innerText = "01.01.2019";
document.getElementById("DatumVon".value = "01.01.2019";

These are some lines I tried in C# in the method "Page_Load" (server side):

this.DatumVon.Text = "01.01.2019";
 

I expected the value of the TextBox to be `01.01.2019`. However, it currently only contains `dd.mmm.yyyy`. How can I change this?

Thank you.