Function date_diff 

pub fn date_diff<DT: DateTimeParts>(from: DT, to: DT) -> DateDiffResult

Calculate the difference between two DateTime instances.

Example

use chrono::prelude::*;
use date_differencer::{DateDiffResult, date_diff};

let date = Local.with_ymd_and_hms(2000, 1, 1, 0, 0, 0).unwrap();
let date_after_1_year_1_day =
    Local.with_ymd_and_hms(2001, 1, 2, 0, 0, 0).unwrap();

assert_eq!(
    DateDiffResult {
        years: 1,
        days: 1,
        ..DateDiffResult::default()
    },
    date_diff(date, date_after_1_year_1_day)
);