You have a date field in Excel formatted as MM/DD/YY or MM/DD/YYYY where M = month, D = day and Y = year. The software imports that field and the date now looks like

YYYYMMDD

which is exactly 8 digits in length and has no spaces, slashes or dashes. This is how the IRS wants to receive a date field.

If you go to File/Print or Print Preview, the software will reformat this 8-digit date field to print as:

MM/DD/YY

so that Copy B sent to the recipient can be easily read.