Formula Checkfield to be true if a Date field is during the previous month.

Greetings Quickbase,

I'm trying to create a formula checkfield that replicates the functionality of a Quickbase report.  I would like this field to be checked if some date field is during the previous month.

For example(the date of this posting is 11/21/2017):

                        * Formula CheckBox Field  |    Date Field
Record 1           Checked                         10/10/2017
Record 2          Unchecked                      11/03/2017
Record 3          Unchecked                       9/15/2017

Any suggestions or work arounds would be much appreciated!

Thanks,

Nate