How to format SystemTime to string?

Question

It seems there is no way I can turn SystemTime into a string. I have to use SystemTime because I need the value returned from std::fs::Metadata::created().

Answer 1

You should use Chrono for its formatting support. Since Chrono v0.4.0 this is much easier, as it now implements direct conversions from std::time::SystemTime:

extern crate chrono;
use chrono::offset::Utc;
use chrono::DateTime;
use std::time::SystemTime;

let system_time = SystemTime::now();
let datetime: DateTime<Utc> = system_time.into();
println!("{}", datetime.format("%d/%m/%Y %T"));

If you wanted the time in local timezone instead of UTC, use Local instead of Utc.

For the full list of formatting specifiers see the Chrono documentation.

Answer 2

The time crate is now a viable alternative to chrono. See the format() method for details on returning a String from an OffsetDateTIme. Also make sure to check the strftime specifiers table when making your formatting string.

use time::OffsetDateTime;
use std::time::SystemTime;

fn systemtime_strftime<T>(dt: T, format: &str) -> String
   where T: Into<OffsetDateTime>
{
    dt.into().format(format)
}

fn main() {
    let st = SystemTime::now();
    println!("{}", systemtime_strftime(st, "%d/%m/%Y %T"));
}

Play