saturating-time

A trait for limits and saturations on types inside [std::time].

• Easy: saturating-time only adds a single trait, [SaturatingTime] that is implemented for various types from the standard library.
• Future-Proof: In the case that [SaturatingTime::saturating_add()] and [SaturatingTime::saturating_sub()] become a part of the standard library, developers would only have to remove the use saturating_time::SaturatingTime line from their code.^{1 2}.
• Portable: The algorithm for determining the limits is portable across operating systems: enjoy this crate from Windows, Darwin, and Linux, across the BSD systems, up to exotic ones such as Hermit OS and Redox.
• Secure: This crate does not make any use of unsafe Rust code.

Overview

saturating-time is a very minimal crate that only exposes a minimal trait: [SaturatingTime].

The trait itself offers the following methods:

• [SaturatingTime::max_value()] – Returns the maximum value for this type.
• [SaturatingTime::min_value()] – Returns the minimum value for this type.
• [SaturatingTime::saturating_add()] – Saturating addition for this type.
• [SaturatingTime::saturating_sub()] – Saturating subtraction for this type.
• [SaturatingTime::saturating_duration_since()] - Saturating time deltas for this type.

This trait is sealed, meaning applications may not implement it themselves. However, this crate implements this trait for two structures:

• [std::time::Instant]
• [std::time::SystemTime]

Example

Add the following to your Cargo.toml:

[dependencies]
saturating-time = "0.3.0"

Now, you can use saturating-time in your code:

use std::time::{Duration, SystemTime};
use saturating_time::SaturatingTime;

// Get the maximum and minimum.
let max = SystemTime::max_value();
let min = SystemTime::min_value();

assert_eq!(max.saturating_add(Duration::new(1, 0)), max);
assert_eq!(min.saturating_sub(Duration::new(1, 0)), min);
assert!(max.saturating_duration_since(SystemTime::UNIX_EPOCH) >= Duration::ZERO);

Standardization Efforts

The eventual goal is to get this functionality into the Rust standard library.

SystemTime

SystemTime::MIN and SystemTime::MAX

There is an ACP that has been approved in November 2025.³ Please follow the tracking issue⁴ for more information about this in particular.

SystemTime::saturating_add() and SystemTime::saturating_sub()

None yet.

Instant

None yet.

License and Copyright

This crate is licensed under MIT OR Apache-2.0. See the respective LICENSE-* files in the repository for more information.