Date and Time in Rust

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:timing
:sccache 1

Comments¶

There are a few 3rd-party Rust crates time, quanta and chrono for handling time/date. The Rust crate time, is recommended. For detailed discussions, please refer to No Time for Chrono .

use std::time::{SystemTime, UNIX_EPOCH};

SystemTime::now()

SystemTime { tv_sec: 1638324570, tv_nsec: 811168245 }

let start = SystemTime::now();
start.duration_since(UNIX_EPOCH).expect("Time went backwards")

1638324597.690945736s

let start = SystemTime::now();
start.duration_since(UNIX_EPOCH).unwrap()

1638324623.948540298s

let start = SystemTime::now();
start.duration_since(UNIX_EPOCH).unwrap().as_secs()

1638324793

let start = SystemTime::now();
start.duration_since(UNIX_EPOCH).unwrap().as_millis()

1638324649987

let start = SystemTime::now();
start.duration_since(UNIX_EPOCH).unwrap().as_nanos()

1638325403263831531

SystemTime itself does not support formatting as string. However, it can be done indirectly by casting SystemTime to chrono::Datetime first.

:dep chrono = "0.4.19"

use std::time::SystemTime;
use chrono::offset::Local;
use chrono::DateTime;

let datetime: DateTime<Local> = SystemTime::now().into();
println!("{}", datetime.format("%Y-%m-%d %H:%M:%S.%f"));

2021-11-30 18:15:06.485079503

Local::now()

2021-11-30T18:15:12.199268942-08:00