If Formula Help Date Range

Hello,

In the attached workbook, I am trying to make an IF formula so if the date in A1 and down is less than 01/01/2017, it returns a 1 in cell B1. I am not sure if I have to format the formula differently for it to know I am typing a date in the IF formula. Can someone please help?

In B1

=IF(A1 < DATEVALUE("1/1/2017"),1,0)

copy down

With your formula like this

=+IF(A1 < 1/1/2017,1,0)

Excel is reading that like this
If A1 is Less Than 1 divided by 1 divided by 2017 Then 1, else 0

To make that be treated as a date, try
=+IF(A1 < "1/1/2017"+0,1,0)
or
=+IF(A1 < DATE(2017,1,1),1,0)