Hi Murtza,
Thanks for your suggestion. Can you go into a bit more detail regarding Marketo's backend process for handling datetimes? Is there a conversion process that I'm unaware of, and if so, can you explain the parameters involved? My initial thought was that Marketo parses datetimes in the exact form in which they are uploaded, irrespective of account time zone.
If you import a file containing a time attribute with the value 2014-06-04 16:00:00, the value will be stored as 4:00 PM (Central Time) on 6/4/2014. If your Marketo instance logging is configured to be in Eastern Time and you view the value in the UI, it will be displayed as 5:00 PM (Eastern Time) on 6/4/2014.