How do I apply RelativeDelta to a PyDate object in pyo3

My code below.

#rust_lib/src/lib.rs

use pyo3::prelude::*;
use pyo3::types::{PyDate};
use relativedelta::RelativeDelta;

#[pyfunction]
fn create_date(_py: Python) -> PyResult<&PyDate> {
    let date = PyDate::new(_py, 2022, 3, 1);
    println!("rust date is {:?}", &date);
    date
}


#[pymodule]
fn rust(py: Python, m: &PyModule) -> PyResult<()> {
    m.add_function(wrap_pyfunction!(create_date, m)?)?;
    Ok(())
}

#python.py

import rust_lib
print('python date is', rust_lib.create_date())

When I run this I get this compiler error (

error[E0369]: cannot add `RelativeDelta` to `Result<&PyDate, PyErr>`
  --> src/lib.rs:40:37
   |
40 |     let changed_date:&PyDate = date + months12;
   |                                ---- ^ -------- RelativeDelta
   |                                |
   |                                Result<&PyDate, PyErr>

How do I fix this? The code runs if I remove the 2 relative delta lines. Do I need to unpack the PyDate and PyErr from the PyResult?