Convert String to Date in Ms Access Query

Use the DateValue() function to convert a string to date data type. That's the easiest way of doing this.

DateValue(String Date) 

In Access, click Create > Module and paste in the following code

Public Function ConvertMyStringToDateTime(strIn As String) As Date
ConvertMyStringToDateTime = CDate( _
        Mid(strIn, 1, 4) & "-" & Mid(strIn, 5, 2) & "-" & Mid(strIn, 7, 2) & " " & _
        Mid(strIn, 9, 2) & ":" & Mid(strIn, 11, 2) & ":" & Mid(strIn, 13, 2))
End Function

Hit Ctrl+S and save the module as modDateConversion.

Now try using a query like

Select * from Events
Where Events.[Date] > ConvertMyStringToDateTime("20130423014854")

--- Edit ---

Alternative solution avoiding user-defined VBA function:

SELECT * FROM Events
WHERE Format(Events.[Date],'yyyyMMddHhNnSs') > '20130423014854'

cdate(Format([Datum im Format DDMMYYYY],'##/##/####') ) 

converts string without punctuation characters into date

Basically, this will not work out

Format("20130423014854","yyyy-MM-dd hh:mm:ss")

the format function will only work if your string has correct format

Format (#17/04/2004#, "yyyy/mm/dd")

And you need to specify, what datatype of field [Date] is, because I can't put this value 2013-04-23 13:48:54.0 under a General Date field (I use MS access2007). You might want to view this topic: select date in between

If you need to display all the records after 2014-09-01, add this to your query:

SELECT * FROM Events
WHERE Format(Events.DATE_TIME,'yyyy-MM-dd hh:mm:ss')  >= Format("2014-09-01 00:00:00","yyyy-MM-dd hh:mm:ss")