20

我正在使用chrono crate；经过一番挖掘，我发现该DateTime类型具有timestamp()可以生成类型纪元时间的功能i64。但是，我找不到如何将其转换回DateTime.

extern crate chrono;
use chrono::*;

fn main() {
    let date = chrono::UTC.ymd(2020, 1, 1).and_hms(0, 0, 0);
    println!("{}", start_date.timestamp());
    // ...how to convert it back?
}
4

3 回答 3

16

您首先需要创建一个NaiveDateTime，然后使用它DateTime再次创建一个：

extern crate chrono;
use chrono::prelude::*;

fn main() {
    let datetime = Utc.ymd(2020, 1, 1).and_hms(0, 0, 0);
    let timestamp = datetime.timestamp();
    let naive_datetime = NaiveDateTime::from_timestamp(timestamp, 0);
    let datetime_again: DateTime<Utc> = DateTime::from_utc(naive_datetime, Utc);

    println!("{}", datetime_again);
}

操场

于 2017-03-03T07:35:05.710 回答
1

您可以使用parse_duration箱子：https ://docs.rs/parse_duration/2.1.0/parse_duration/

extern crate parse_duration;
use parse_duration::parse;
use std::time::Duration;

fn main() {
    // 1587971749 seconds since UNIX_EPOCH
    assert_eq!(parse("1587971749"), Ok(Duration::new(1587971749, 0)));

    // One hour less than a day
    assert_eq!(parse("1 day -1 hour"), Ok(Duration::new(82_800, 0)));

    // Using exponents
    assert_eq!(
        parse("1.26e-1 days"),
        Ok(Duration::new(10_886, 400_000_000))
    );

    // Extra things will be ignored
    assert_eq!(
        parse("Duration: 1 hour, 15 minutes and 29 seconds"),
        Ok(Duration::new(4529, 0))
    );
}
于 2020-04-28T02:52:04.960 回答
1

不确定我是否遗漏了某些东西，或者 chrono 同时扩展了它的功能集，但是它的 2021 年，至少从 chrono 0.4.0 开始，似乎有一种更清洁的方法来做到这一点：

https://docs.rs/chrono/0.4.19/chrono/#conversion-from-and-to-epoch-timestamps

use chrono::{DateTime, TimeZone, Utc};

// Construct a datetime from epoch:
let dt = Utc.timestamp(1_500_000_000, 0);
assert_eq!(dt.to_rfc2822(), "Fri, 14 Jul 2017 02:40:00 +0000");

// Get epoch value from a datetime:
let dt = DateTime::parse_from_rfc2822("Fri, 14 Jul 2017 02:40:00 +0000").unwrap();
assert_eq!(dt.timestamp(), 1_500_000_000);

所以你的完整转换应该是这样的：

extern crate chrono;
use chrono::*;

fn main() {
    let start_date = chrono::Utc.ymd(2020, 1, 1).and_hms(0, 0, 0);
    let ts = start_date.timestamp();
    println!("{}", &ts);
    let end_date = Utc.timestamp(ts, 0);
    assert_eq!(end_date, start_date);
}
于 2021-11-21T20:18:26.790 回答