Timezone-aware datetime library for the Rust programming language (doc)
hourglass provides support for timezone, datetime arithmetic and take care
of subtleties related to time handling, like leap seconds.
Add the following in your Cargo.toml:
[dependencies]
hourglass = "0.*"And put this in your crate root:
extern crate hourglass;Because a datetime without a timezone is ambiguous and error-prone, hourglass
only exposes a Datetime that is timezone-aware. The creation of a Timezone
is the entry point of the API. hourglass provides several way of creating
a Timezone:
use hourglass::Timezone;
let utc = Timezone::utc();
let local = Timezone::local().unwrap();
let paris = Timezone::new("Europe/Paris").unwrap();
let fixed = Timezone::fixed(-5 * 3600);A Datetime is created for a specific timezone and can be projected in another
timezone:
use hourglass::Timezone;
let utc = Timezone::utc();
let paris = Timezone::new("Europe/Paris").unwrap();
// Create a `Datetime` corresponding to midnight in Paris timezone...
let t = paris.datetime(2015, 12, 25, 0, 0, 0, 0).unwrap();
// ... and project it into UTC timezone.
let t_utc = t.project(&utc);
assert_eq!(t_utc.date(), (2015, 12, 24));
assert_eq!(t_utc.time(), (23, 0, 0, 0));Datetime arithmetic is performed with a Deltatime. Several granularities
are available when handling Deltatime and will yield different results:
use hourglass::{Timezone, Deltatime};
let utc = Timezone::utc();
let t = utc.datetime(2015, 6, 30, 0, 0, 0, 0).unwrap();
let t_plus_1_day = t + Deltatime::days(1);
let t_plus_86400_sec = t + Deltatime::seconds(86400);
assert_eq!(t_plus_1_day.date(), (2015, 7, 1));
// One leap second was inserted this day.
assert_eq!(t_plus_86400_sec.date(), (2015, 6, 30));
assert_eq!(t_plus_86400_sec.time(), (23, 59, 60, 0));Two Datetime can also be compared:
use hourglass::{Timezone, Deltatime};
let utc = Timezone::utc();
let t0 = utc.datetime(2015, 6, 30, 0, 0, 0, 0).unwrap();
let t1 = utc.datetime(2015, 7, 1, 0, 0, 0, 0).unwrap();
assert_eq!(t0 < t1, true);
assert_eq!(t0 >= t1, false);
assert_eq!(t1 == t1, true);
assert_eq!(t1 - t0, Deltatime::seconds(86401));hourglass also provides the Every iterator for scheduling a loop
body execution at regular time interval:
use hourglass::{Timezone, Deltatime, Timespec, Every};
let paris = Timezone::new("Europe/Paris").unwrap();
let until = Timespec::now() + Deltatime::seconds(5);
for t in Every::until(Deltatime::seconds(1), until) {
println!("it is {} in Paris", t.to_datetime(&paris).format("%H:%M:%S").unwrap());
}The Range iterator can be used to iterate over a range of Timespec:
use hourglass::{Deltatime, Timespec, Range};
let now = Timespec::now();
let then = now + Deltatime::minutes(1);
for t in Range::new(now, then, Deltatime::seconds(1)) {
println!("tick {}", t.seconds());
}