Date Differencer

Calculate the time interval between two DateTime instances and output the result in years plus months plus days plus hours plus minutes plus seconds plus nanoseconds (instead of representing the same duration in different units). This library is useful for lifespan check and age calculation.

Usage

use chrono::prelude::*;

use date_differencer::{date_diff, date_time_diff, add_date_time_diff};

let a = Local.with_ymd_and_hms(2022, 4, 6, 0, 0, 0).unwrap();
let b = Local.with_ymd_and_hms(2023, 6, 9, 1, 0, 0).unwrap();

println!("{:?}", date_diff(a, b));
/*
{
    "years": 1,
    "months": 2,
    "days": 3
}
*/

println!("{:?}", date_time_diff(a, b));
/*
{
    "years": 1,
    "months": 2,
    "days": 3,
    "hours": 1,
    "minutes": 0,
    "seconds": 0,
    "nanoseconds": 0
}
*/

println!("{}", add_date_time_diff(a, &date_time_diff(a, b)).unwrap()); // the same as b

This library can handle leap years and odd/even number of days in a month correctly. The result of following code is a bit confusing but reasonable.

use chrono::prelude::*;

use date_differencer::date_diff;

let a = Local.with_ymd_and_hms(2020, 2, 27, 0, 0, 0).unwrap();
let b = Local.with_ymd_and_hms(2021, 3, 1, 0, 0, 0).unwrap();

println!("{:?}", date_diff(a, b));
/*
{
    "years": 1,
    "months": 0,
    "days": 2
}

Explanation:
    1. 2020-02-27 + 1 year -> 2021-02-27
    2. 2021-02-27 + 2 days -> 2021-03-01 (2021-02 has 28 days)
*/

println!("{:?}", date_diff(b, a));
/*
{
    "years": -1,
    "months": 0,
    "days": -3
}

Explanation:
    1. 2021-03-01 - 1 year -> 2020-03-01
    2. 2020-03-01 - 3 days -> 2020-02-27 (2020-02 has 29 days)
*/

Crates.io

https://crates.io/crates/date-differencer

Documentation

https://docs.rs/date-differencer

License

MIT