Date Evaluation Question

I have a DATE1 and a DATE2 field whose data looks like this:

20180101
20171231
20171228

I need to do some analysis whereby I'll be looking at DATE1 field and comparing it to DATE2 field to gather all records that have a DATE2 field "within 45 days" of the DATE1 field.

Is it better to leave the field in the coded format "YYYYMMDD" or is it better to convert the fields to a true "DATE" format and calculate using an actual DATE formatted field?

Thanks
CRXI