Pulling records based on Date in JDBC

How can I return all customers whose last appointment_date was 11 months ago from the date today? Or 12 months ago from the date in a month from today?

The first statement is working where I get the appointment from_date and compare it to the current date and return all the appointments that are happening tomorrow:

SELECT  appointment.id, 
        appointment.from_date 
WHERE   (julianday('now') - julianday(appointment.from_date)) = 1

But for the second statement I cant figure out how to return all customers whose last appointment date was 11 months ago from the current date?

SELECT  customer.id, 
        customer.last_appointment_date
FROM    customer 
WHERE   datediff(month, customer.last_appointment_date, DATEADD(month, getDate())) = 12

datediff() doesn't work because I am using SQLite and it is not a recognised function.

Any help would be greatly appreciated.

EDIT: I am running these query's in my code in netbeans i am using the sqllitejdbc driver to run them through prepared statements

I have edited, its because i am running through netbeans, everytime i use datediff(month, customer.last_appointment_date, DATEADD(month, getDate())) = 12 it returns month not a valid column - it doesnt recognise it as a valid date part?

returned: Caused by: java.sql.SQLException: [SQLITE_ERROR] SQL error or missing database (no such column: month)