Hi, I also have the same problem, and unfortunately, the [DisplayFormat] attribute dont work.

But: If you use on-page editor properties, you can use displaytemplates as a workaround, ex.

On your pagetype:

[UIHint("MyDateFormat"]
public virtual DateTime MyDate {get; set;}

Then add a displaytemplate in ~/Views/Shared/DisplayTemplates/MyDateFormat.cshtml, like so:

@model DateTime
@Model.ToString("yyyy-MM-dd HH:mm:ss")

finally, in your page template (or wherever you are displaying the date property:

<div @Html.EditAttributes(m => m.MyDate)>@Html.DisplayFor(m => m.Mydate, "MyDateFormat")</div>

The reason you need the displaytemplate in /Shared, and not directly under ex. your page controllers view folder is that all properties rendered on the server side when you edit a value is rendered using the "PropertyRenderer" controller in EPiServer, this controller will not see any displaytemplates under other folders than the shared (or its own).