Sounds like a UTC time offset issue. Please check to see if your timezone settings are correct, as described in this help aritcle:
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.
I am not sure. I am going to get the right person to look at this thread.
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.
I have follow-up question so we can provide more detail. What import mode are you using for this?
I'm uploading a CSV to a list. Can you tell me why Marketo processes (date)times in CT and converts them according to user time zone instead of just processing them in that time zone?