Date field changing from UK to US culture upon SaveChanges (EF6.1) - asp.net

Question

I am using a custom overloaded SaveChanges to implement some auditing functionality. The functionality works perfectly with the exception of some unexpected behaviour in relation to dates. In this example I'm changing a date field value from 1st May 2014 to 2nd May 2014:
A change is made to the database here:
Public Function UpdateTask(request As DataSourceRequest, ThisTask As JobTasksVM) As JsonResult
Dim cu As ApplicationUser = GetCurrentUser()
Dim CurrentTask = db.events.Find(ThisTask.id)
CurrentTask.start_date = ThisTask.start '<--- 2/5/2014 (ie 2nd May 2014), was previously 1/5/2014
CurrentTask.date = ThisTask.end
CurrentTask.task_name = ThisTask.Title
db.SaveChanges(cu.Employee_id)
End Function
This is intercepted by my custom SaveChanges:
Public Overloads Function SaveChanges(userID As Integer) As Integer
For Each entry As dbentityentry In Me.ChangeTracker.Entries().Where(Function(e) e.State <> EntityState.Unchanged)
Dim startOriginal As DateTime = entry.OriginalValues.Item("start_date")
Dim StartCurrent As DateTime = entry.CurrentValues.Item("start_date")
etc....
The bizarre thing is that whilst CurrentTask.start_date that is committed clearly shows the correct (UK) date of 2/5/2014 (2nd May 2014) the values within the overloaded SaveChanges are:
startOriginal: 5/1/2014 (ie 5th Jan 2014) <-- seems to have changed to US culture
startCurrent: 2/5/2014 (ie 2nd May 2014) <---as expected
I need to use the Original values in my audit functionality so this is causing a problem. I have also tried:
entry.CurrentValues.SetValues(entry.GetDatabaseValues)
But this also loads in the erroneous (ie US format 5/1/2014) into the start_date field.
I've checked all the culture settings on the system and they are all correctly English-UK. This behaviour seems fundamentally inconsistent - am I missing something?!
Thanks

Answer 1

DateTime types do not have a format, they are simply a value (number of ticks since 1/1/0001).
You did not say where you are seeing the "wrong" format, whether ToString() output or in intellisense. If you use ToString to the Output window, you should see the UK format since ToString will use/respect the local culture setting of the computer.
Intellisense is culture agnostic and tries to use an unambiguous format: MM/dd/yyyy. This is the same "format" or order you have to use when creating a DateTime var from a literal:
Dim dt As DateTime = #1/5/2014# ' e.g. MM/dd/yyyy
' same as:
Dim dt As New DateTime(1, 5, 2014) ' mm, dd, yyyy
This is InvariantCulture (not US). When you hold the mouse over the var, the VB IDE will use the same order. It tries to make clear it is using the required literal/InvariantCulture format by displaying it with the hashes: #1/5/2014#.
Dim dt As DateTime = #2/11/2011#
Console.WriteLine(dt.ToString)
In the US, 2/11/2011 will display based on the culture
In the UK, it will be 11/2/2011
Intellisense will be #2/11/2011#