I found this post on the old forum:

http://forum.umbraco.org/yaf_postst6303_Change-Documents-Created-Date.aspx

An can't for the life of me find it in the new forum (any advice on how to do this?), but I wanted to post an answer to the question, or at least my take on it.

My way to solve the problem of importing old content is to include a field in the document type called 'datePublished'. This is the set, then in an event I check for this and override the Created Date and clear out the 'datePublished'.

I have an Events class which inherits from ApplicationBase and in the constructor (extract shown below) establish the events (remember to always allow them to the turned off) (apologies for the VB.NET - client requirement)

        settingValue = ConfigurationManager.AppSettings.Get("EnableUpdateCreatedDateEvent")
        If Not String.IsNullOrEmpty(settingValue) AndAlso settingValue.ToLower() = "true" Then
            AddHandler Document.BeforeSave, AddressOf Me.UpdateCreatedDate
        End If

The code for updating the Create Date is easy too.

    Private Sub UpdateCreatedDate(ByVal sender As Document, ByVal e As SaveEventArgs)
        'if the document has a property called 'datePublished' then if it has a value and it is a date, then we'll use it to override the main date and then clear the field

        Dim PROPERTY_NAME As String = "datePublished"
        Dim datePublishedValue As String = Ed.Helper.Umbraco.GetDocumentPropertyValue(sender, PROPERTY_NAME)
        Dim datePublished As DateTime

        If Not String.IsNullOrEmpty(datePublishedValue) AndAlso DateTime.TryParse(datePublishedValue, datePublished) Then
            sender.CreateDateTime = datePublished
            ED.Helper.Umbraco.DeleteDocumentProperty(sender, PROPERTY_NAME)
        End If

    End Sub

The "ED.Helper" is just a helper class that I created and use extensively to hide away the exceptions that Umbraco raises. In normal Umbraco you can delete a property by calling its 'delete()' method and you can access it's value using code something like the following:

            string retval = null;

            if (content != null)
            {
                Property property = null;
                try
                {
                    property = content.getProperty(propertyName);
                }
                catch { }
                if (property != null)
                {
                    retval = property.Value.ToString();
                }
            }

            // return the result
            return retval;

Hopfully that helps someone, if not me in the future. Happy to answer any questions.

Cheers

Steve