How to go back on the Schedule E Worksheet

It is part of the questions asked in the Property Profile section of your Rental Income and Expenses part of your return.  

The question about personal use days comes up when you see the question asking if the property was rented all year.  If you answer 'no', then there are follow-up boxes to enter the number of days rented and the number of days of personal use.

If the property was converted to or from personal use during the year, be sure that you are only entering personal days that occurred while the property was a rental property, not before or after a conversion.