How to show entires from past 12 months?
I used the after parameter in my query.

{% set query = craft.entries({
    after: now|date_modify('5:00 -12 months')
}).all() %}


I'm grabbing todays date, then modifying with the date_modify filter. The 5:00 string makes sure it changes at the same time everyday. 

I got the usage of date_modify from carlcs's answer here: How to only show entries older than 12 months