My Locale is set to Australia (Sydney) and Time Zone is set to Australia/Sydney (EST).
At the moment when I do a list import, I need to convert the date format from dd/mm/yyyy to mm/dd/yyyy in the CSV file and then import. Once the import is complete, Marketo displays it as dd/mm/yyyy as desired. Importing datetime is more complex and requires the import format to be in Marketo timezone.
It would be great if we can import date and datetime in the locale and timezone set in Admin.