I have created a "Date Picker With Time" property on my NewsItem documents types, to handle a user editable date for news items.

I do however want that field to automatic get set to the time of the first publish. So i created a CustomEventHandler like this.

public class CustomEventHandlers : ApplicationEventHandler
{
    protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        ContentService.Published += ContentServicePublished;
    }
    private void ContentServicePublished(IPublishingStrategy sender, PublishEventArgs<IContent> args)
    {
        foreach (IContent node in args.PublishedEntities)
        {
            if (node.HasProperty("firstPublished") && node.GetValue("firstPublished") == null)
            {
                node.SetValue("firstPublished", DateTime.Now);
            }
        }
    }
}

But guess what? I won't work. I have debugged the code and the line "node.SetValue" is running? Does the "Date Picker with Time" dont use DateTime data?