Hi,
there is no native support for this kind of request, however you can modify the Grid web part (https://docs.kentico.com/display/K9/Customizing+web+parts). Please open Visual Studio and look for ~\CMSWebParts\Viewers\Documents\cmsdatagrid.ascx.cs. There is method called InitColumns. In this method you can check if the current item is of type datetime and if this would be the case, you can simply modify it according your needs.
There is sample how the code can look like:
BoundColumn col = new BoundColumn();
column = col;
col.DataField = mName;
// Does the name of the column contain "Date" ? If so, let's display it as a short date format
if (mName.Contains("Date"))
{
col.DataFormatString = "{0:d}";
}