This is what I have done; I am not sure if this is valid and will bring in the outcome that I want
case when lost_renewal_start_date between getdate() and dateadd(day, -365, getdate())
then true
else false
end as churned_within_last_12_months
Try the following:
select *,
case when
lost_renewal_start_date > (current_date - interval '1 year')::date
and lost_renewal_start_date <= current_date
then true
else false
end as churned_within_last_12_months
from test
See a demo on Postgres from here.