Science ❯ Physics

Time Measurement

Atomic Clocks Chronometry Chronobiology Leap Seconds Equation of Time Daylight Saving Time Chronology Seasonal Changes Temporal Changes Atomic Time Universal Time Coordinated (UTC) Time Standards Standards of Time Atomic Physics Day Duration Time Signals Standards Organizations Attosecond Attoseconds Gravitational Time Dilation Standards

Clocks Spring Forward Sunday: What to Know About 2026 Daylight Saving Time

Health experts warn the spring shift disrupts sleep, raising short‑term safety risks.

NIST Restores U.S. Time After Colorado Outage Causes Microsecond Drift

Winter Solstice Arrives Sunday at 3:03 p.m. GMT, Marking Year’s Shortest Day

Record-Short Days Renew Debate Over First-Ever Negative Leap Second

Earth Sets Second-Shortest Day of 2025 as Spin Continues to Accelerate

New Projections Confirm Record-Short Days This July and August

Earth's Spin Breaks Short-Day Records as Timekeepers Halt 2025 Leap Second