I'm trying to import my list, including the DOB field. At first, I received an error message, saying, "born_at is not a valid format. This should be a date, like MM/DD/YYYY". I went into excel and realized there is no date format that matches the format NB is requesting. So, I had to create  custom format to apply to all cells in the column. I fixed that, tried to upload the newly saved file, then got the same error message. I think this is happening b/c although the cell shows the correct date format, when I click on the cell, the formula bar shows the original date format (ex, 3/13/2001 instead of 03/13/2001 like listed in the cell). Any suggestions?