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Time Zone Guide for Remote Work: Why Scheduling Is Harder Than You Think

•10 min read•By KBC Grandcentral Research Team

There are 38 different UTC offsets in use today — not 24, because some time zones use 30 or 45-minute offsets (India is UTC+5:30; Nepal is UTC+5:45). Remote teams spanning more than 8 time zones have virtually no overlap in standard working hours. Understanding the real landscape of global time is the foundation of async-first work.

One Moment, Seven CitiesLos Angeles9:00 AMUTC-8New York12:00 PMUTC-5London5:00 PMUTC+0Dubai9:00 PMUTC+4Mumbai10:30 PMUTC+5:30Singapore1:00 AM+1UTC+8Sydney4:00 AM+1UTC+11LA–NY: 3hr gap · NY–London: 5hr gap · London–Singapore: 8hr gapLA to Sydney span: 19 hours — zero overlap in standard work hours38 UTC Offsets, One Global Team

Key Takeaways

  • 38 UTC offsets exist — not 24, due to half-hour and 45-minute offset zones like India and Nepal
  • Always use UTC for internal records — never use "EST" or "PST" as they're ambiguous during DST transitions
  • DST causes chaos — the US and EU switch on different dates, creating 2-week windows where offsets shift unexpectedly
  • Golden hours for global teams: 9–10am ET overlaps with both West Coast morning and early European afternoon
  • Async-first is the default for teams spanning more than 8 hours — synchronous meetings become the exception

UTC vs Time Zone Names: Why Programmers Use UTC

UTC (Coordinated Universal Time) is the time standard the world synchronizes to — it has no daylight saving offset and no political changes. Time zone names like "EST" (Eastern Standard Time) and "PST" (Pacific Standard Time) are ambiguous: EST is UTC-5, but "Eastern Time" during summer (EDT) is UTC-4. Three-letter time zone abbreviations are not unique — "IST" refers to Indian Standard Time, Irish Standard Time, and Israel Standard Time.

For any software, database, or API, store times in UTC. Display in local time zones only for the user interface. The IANA Time Zone Database (Olson database) — used by Python, Java, Node.js, PostgreSQL, and virtually every modern system — identifies zones by region/city name: "America/New_York", "Europe/London", "Asia/Kolkata". These names are stable even when a government changes its UTC offset.

The DST Problem

Daylight Saving Time (DST) is observed by about 70 countries, but they switch on different dates. The US switches on the second Sunday of March; most of Europe switches on the last Sunday of March. This creates a 2-3 week window where the US-UK offset is 4 hours instead of 5, and the US-Europe offset is 6 instead of 7.

Notable DST Edge Cases

Arizona:Most of Arizona (except Navajo Nation) does not observe DST — creating variable offsets vs California depending on time of year.
India:Never observes DST. Uses UTC+5:30 year-round — always a half-hour offset that confuses automatic scheduling tools.
Australia:States observe DST differently — Queensland never does, while NSW and Victoria do. Intra-country Australian scheduling has DST complexity.
Russia:Abolished DST in 2014, staying on "summer time" permanently — effectively shifting all Russian clocks forward by 1 hour indefinitely.

Scheduling for Global Remote Teams

Best Practices

  • ✓ Always include UTC offset in meeting invites: "2pm ET (19:00 UTC)"
  • ✓ Rotate meeting times so the same person doesn't always take early/late meetings
  • ✓ Record all meetings — make async viewing the default, not the exception
  • ✓ Use World Time Buddy or a converter before scheduling
  • ✓ Designate "async hours" — blocks where responses are not expected

Overlap Windows (for common pairings)

New York ↔ London2–5pm ET
New York ↔ Singapore8–10am ET
London ↔ Singapore8–9am UK
LA ↔ LondonMinimal (5–9am PT)
NY ↔ India8–10am ET

Convert Time Zones Instantly

Time Zone Converter

Convert times between any of 400+ time zones. Find overlapping work hours for global teams, view DST transitions, and schedule meetings across continents.

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