A Brief History of Standard Time
From local solar time to GMT, time zones, and the IANA database today.
Before railways and telegraphs, towns kept **local solar time** — noon when the sun crossed the meridian. Train schedules pushed **standard time zones**: the 1884 International Meridian Conference set Greenwich as 0°, evolving into today's IANA system and UTC Basics.
Milestones
- 1884: Greenwich as prime meridian (UK Time: GMT and BST)
- 1883 US: railroads adopt four standard zones
- 1972: UTC replaces GMT as atomic-time reference
- Today: IANA tz database (What Is the IANA Time Zone Database)
Why it matters now
- Zones are conventions — countries can change rules
- History explains Worldwide Daylight Saving Abolition Trends and news headlines
- Do not schedule global calls with 1800s solar-time intuition
- Tools: our Convert and Countries
DST origins: DST Guide; maintenance: Keeping Time Zone Data Updated.