Working with Dates in Rust: Overview of Time and Date Libraries

Working with Dates in Rust: Overview of Key Libraries

Rust is a systems programming language that places a strong emphasis on safety and performance. However, working with dates and times is always a complex task due to time zones, leap seconds, and formats. The Rust ecosystem has several mature libraries that solve these problems. In this article, we will look at three main libraries: chrono, time, and jiff, and show how to use them in practice.

1. Chrono — The Main Standard

chrono is the most popular library for working with dates in Rust. It provides a full set of tools: parsing, formatting, date arithmetic, time zone handling, and serialization via serde.

Installation via Cargo.toml:

[dependencies]chrono = { version = "0.4", features = ["serde"] }

Basic usage example:

use chrono::{NaiveDate, NaiveDateTime, Duration, Utc, Local};

fn main() {    // Current date and time in UTC    let utc_now = Utc::now();    println!("Now in UTC: {}", utc_now.format("%Y-%m-%d %H:%M:%S"));

    // Local time    let local_now = Local::now();    println!("Local time: {}", local_now.format("%d.%m.%Y %H:%M"));

    // Creating a specific date    let date = NaiveDate::from_ymd_opt(2025, 3, 14).unwrap();    println!("Date: {}", date);

    // Date arithmetic    let next_week = date + Duration::days(7);    println!("In a week: {}", next_week);

    // Parsing a string    let parsed = NaiveDateTime::parse_from_str(        "2025-12-31 23:59:59",        "%Y-%m-%d %H:%M:%S"    ).unwrap();    println!("Parsed: {}", parsed);}

2. The Time Library — A Modern Alternative

time is a newer and stricter library, developed with the lessons learned from chrono's mistakes. It offers a clear separation between types: Date, Time, OffsetDateTime, and PrimitiveDateTime. It supports macros for convenient date creation.

Installation:

[dependencies]time = { version = "0.3", features = ["macros", "serde"] }

Examples:

use time::{Date, Time, OffsetDateTime, macros::datetime, Duration};

fn main() {    // Current time    let now = OffsetDateTime::now_utc();    println!("Now: {}", now);

    // Creating a date using a macro    let meeting = datetime!(2025-06-15 14:30:00 +03:00);    println!("Meeting: {}", meeting);

    // Extracting components    let date = meeting.date();    let time = meeting.time();    println!("Date: {}, Time: {}", date, time);

    // Calculating the difference    let deadline = datetime!(2025-12-31 00:00:00 UTC);    let diff = deadline - now;    println!("Until deadline: {} days", diff.whole_days());

    // Formatting    let formatted = now.format(        &time::format_description::well_known::Rfc3339    ).unwrap();    println!("RFC 3339: {}", formatted);}

Important: The time library is part of the official Rust organization and is considered safer as it avoids panics in most methods (uses Result).

3. Jiff — The New Star

jiff is a relatively new library that focuses on ergonomics and performance. Its main feature is automatic time zone detection and built-in calendar support (Gregorian, Islamic, Hebrew).

Installation:

[dependencies]jiff = "0.1"

Usage example:

use jiff::{Zoned, Timestamp, Unit};

fn main() {    // Current time with time zone    let now = Zoned::now();    println!("Current time: {}", now);

    // Creating from a timestamp    let ts = Timestamp::new(1_700_000_000, 0