universal-time

Cross-platform time primitives for Rust that can run in any envuironment.

Why

universal-time gives you a single API for:

• Instant for monotonic elapsed-time measurements
• SystemTime for wall-clock timestamps
• Trait-based clock injection for platforms without built-in time access

Quick Start

use universal_time::{Instant, SystemTime, UNIX_EPOCH};

fn main() {
    let start = Instant::now();
    let now = SystemTime::now();
    let elapsed = start.elapsed();
    let since_epoch = now.duration_since(UNIX_EPOCH).unwrap_or_default();

    println!("elapsed = {:?}", elapsed);
    println!("since epoch = {:?}", since_epoch);
}

For more examples, check out the examples directory.

Panic Behavior

In no_std mode, and in std mode on wasm32-unknown-unknown, both Instant::now() and SystemTime::now() panic when:

• no global context has been installed, or
• installed context returns None for that clock type

This is intentional so missing time sources fail fast instead of silently returning fake timestamps.

Concurrency Notes

• std: global context uses OnceLock
• no_std with atomics: global context uses lock-free once initialization
• no_std without atomics: fallback expects single-threaded startup initialization