Tracking Issue for `SystemTime::MIN` and `SystemTime::MAX`

Feature gate: #![feature(time_systemtime_limits)]

This is a tracking issue for https://github.com/rust-lang/libs-team/issues/692

Public API

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

// Adding the smallest possible Duration to SystemTime::MAX shall fail ...
assert!(SystemTime::MAX.checked_add(Duration::new(0, 1)).is_none());

// ... whereas subtracting it shall be fine.
assert!(SystemTime::MAX.checked_sub(Duration::new(0, 1)).is_some());

// Subtracting the smallest possible Duration from SystemTime::MIN shall fail ...
assert!(SystemTime::MIN.checked_sub(Duration::new(0, 1)).is_none());

// ... whereas adding it shall be fine.
assert!(SystemTime::MIN.checked_add(Duration::new(0, 1)).is_some());

Steps / History

• ACP: rust-lang/libs-team#692
• Implementation: #148825
• Final comment period (FCP)^1
• Stabilization PR

Unresolved Questions

• What should the bounds be on 32-bit platforms? See discussion in https://github.com/rust-lang/rust/pull/148825#discussion_r2548241009. Maybe better resolved by using 64-bit wide APIs on 32-bit platforms (such as __clock_gettime64 or clock_gettime_nsec_np)

Start by reading implementation PR #148825 and the linked discussion about 32-bit platform bounds. Review the feature-gated SystemTime::MIN and SystemTime::MAX API and the stabilization requirements. Done means resolving the outstanding bounds question, completing the final comment period, and opening or supporting a stabilization PR.