Understanding Time Zones
Time zones were established in the late 19th century to standardize timekeeping across different regions. Before their adoption, every city set its own local time based on the position of the sun, which made coordinating train schedules (and later, telecommunications) nearly impossible.
Today, the world is divided into 24 primary time zones, each roughly 15 degrees of longitude wide. However, political and geographical factors mean that many countries and regions use modified time zones that don't follow neat longitudinal lines. For example:
- China uses a single time zone (UTC+8) despite spanning five geographical time zones. This means that in western China, the sun may not rise until 10 AM local time.
- India uses UTC+5:30 — a half-hour offset that doesn't align with the standard one-hour increments most countries use.
- Nepal goes even further with UTC+5:45, making it one of the few countries with a 45-minute offset.
- Russia spans 11 time zones (UTC+2 to UTC+12), the most of any single country.
UTC: The Universal Reference Point
Coordinated Universal Time (UTC) is the global standard from which all time zones are calculated. When you see "UTC+9" (like Japan and Korea), it means that location is 9 hours ahead of UTC. "UTC-5" (like New York in winter) means 5 hours behind. UTC itself is based on atomic clocks and doesn't observe Daylight Saving Time, making it the most reliable reference for international scheduling.
TimeMeet uses UTC as the backbone of its timetable, showing you the UTC time in the first column alongside each city's local time. This makes it easy to communicate across teams: instead of saying "Let's meet at 3 PM my time," you can reference a specific UTC time that everyone can convert.
Daylight Saving Time (DST) Explained
Daylight Saving Time is the practice of advancing clocks by one hour during warmer months so that evenings have more daylight. While the concept seems simple, DST is one of the biggest sources of scheduling confusion for international teams.
Why DST Causes Scheduling Chaos
The problem isn't DST itself — it's that different countries change their clocks on different dates, and some don't observe DST at all. Consider this scenario:
- The United States switches to DST on the second Sunday of March and reverts on the first Sunday of November.
- The European Union switches on the last Sunday of March and reverts on the last Sunday of October.
- Australia (southern hemisphere) switches on the first Sunday of October and reverts on the first Sunday of April — the opposite season.
- Countries like Japan, Korea, China, India, and most ofAfrica don't observe DST at all.
This means that during the "DST gap" weeks (when one country has changed but another hasn't), the time difference between two cities can shift. For example, New York and London are normally 5 hours apart, but for a few weeks in March (when the US has sprung forward but the UK hasn't yet), they're only 4 hours apart.
How TimeMeet Handles DST
TimeMeet uses the IANA timezone database (also known as the Olson database), the same authoritative source used by operating systems, programming languages, and major tech companies. When you select a date in TimeMeet, it automatically calculates whether DST is in effect for each city on that specific date, ensuring accurate time conversions every time.
Pro tip: If you schedule recurring meetings with people in different DST regions, review the meeting time twice a year around the DST transition dates (March and October/November) to make sure the time still works for everyone.
10 Tips for Scheduling Across Time Zones
Use a Visual Tool
Don't try to do timezone math in your head. Use a visual tool like TimeMeet to see the overlap between working hours at a glance. Mental arithmetic with time zones is error-prone, especially when DST is involved.
Rotate Meeting Times
If there's no time that works perfectly for everyone, rotate meeting times so the inconvenience is shared. Don't make the same person always attend meetings at 6 AM or 10 PM. Fairness builds trust in distributed teams.
Always Specify the Time Zone
When communicating meeting times, always include the timezone. Instead of "Let's meet at 3 PM," say "Let's meet at 3 PM EST (UTC-5)." Even better, share a TimeMeet link or calendar invite that automatically shows each participant's local time.
Respect the "Golden Hours"
The "golden hours" for meetings are typically 9 AM to 6 PM local time. Try to schedule within these hours for all participants. If that's not possible, prioritize avoiding nighttime hours (10 PM to 6 AM) for anyone.
Account for DST Transitions
Set calendar reminders for DST transition dates in your participants' countries. Review recurring meetings after each transition to ensure times still work. TimeMeet's date selector helps you check specific dates.
Use Asynchronous Communication First
Not everything needs a meeting. For teams spread across many time zones, default to asynchronous communication (email, shared documents, recorded video updates) and reserve synchronous meetings for discussions that truly require real-time interaction.
Keep Meetings Short
When someone is attending a meeting outside their normal hours, respect their time by keeping it concise. Have a clear agenda, start on time, and end early if possible. A focused 30-minute meeting is better than a rambling 90-minute one.
Record Important Meetings
If a meeting time doesn't work for all stakeholders, record it and share the recording with those who couldn't attend. Pair the recording with written notes or action items so they can catch up efficiently.
Consider Cultural Working Hours
Standard working hours vary by culture. In Spain, lunch breaks can extend from 2 to 4 PM. In some Middle Eastern countries, the workweek runs Sunday to Thursday. In Japan, leaving before your boss is sometimes frowned upon, meaning late meetings may be more accepted.
Bookmark Your Favorite City Combinations
If you frequently schedule between the same set of cities, bookmark your TimeMeet setup so you can quickly check availability without re-selecting cities each time.
Common Time Zone Pitfalls
Confusing EST and ET
"EST" (Eastern Standard Time) specifically refers to UTC-5 and is only used during winter. During summer, the eastern US uses "EDT" (Eastern Daylight Time, UTC-4). The safe abbreviation is "ET" (Eastern Time), which covers both. The same applies to PST/PDT/PT, CST/CDT/CT, and other US time zones.
Forgetting the International Date Line
When scheduling between locations on opposite sides of the International Date Line (e.g., Los Angeles and Sydney), a meeting on "Monday afternoon" for one city might be "Tuesday morning" for the other. Always confirm the date along with the time.
Assuming Fixed Time Differences
The time difference between two cities isn't always constant. Due to DST differences, the offset between London and New York fluctuates between 4 and 5 hours throughout the year. Between New York and Sydney, the difference can range from 14 to 16 hours depending on the time of year.
Ignoring Half-Hour and Quarter-Hour Offsets
Not all time zones use whole-hour offsets from UTC. India (UTC+5:30), Iran (UTC+3:30), Nepal (UTC+5:45), and parts of Australia (UTC+9:30) use non-standard offsets. Always use a tool like TimeMeet rather than simple math to account for these.
Best Practices for Remote Teams
Establish Core Overlap Hours
Identify a window of 2–4 hours when all team members are available during reasonable hours. This becomes your "core hours" for meetings, pair programming, and real-time collaboration. All other communication should default to async.
Document Time Zones in Team Profiles
Make sure every team member's time zone is visible in your communication tools (Slack profile, email signature, etc.). This simple step prevents countless scheduling mistakes and helps team members naturally develop awareness of each other's availability.
Use a Shared World Clock
Keep a shared world clock visible in your team's communication channel showing the current time in each team member's location. Many tools including TimeMeet can help with this. When you see it's 11 PM for a colleague, you naturally hold off on sending a non-urgent message.
Create a Meeting-Free Zone
Designate certain days or time blocks as meeting-free to give team members uninterrupted focus time. This is especially valuable for team members in extreme time zones who might otherwise have their entire day fragmented by meetings scheduled for others' convenience.
Be Explicit About Urgency
When working across time zones, messages often arrive while the recipient is sleeping. Establish clear guidelines for what warrants an immediate notification versus what can wait until their next working day. Most things can wait.
Time Zone Etiquette
Working across time zones isn't just a logistical challenge — it's a cultural one. Here are some etiquette guidelines that help build trust and respect in globally distributed teams:
- Don't schedule meetings during someone's nighttime unless absolutely necessary and agreed upon in advance. If you must, acknowledge the inconvenience and offer to rotate the burden.
- Start and end meetings on time. When someone wakes up early or stays up late for a call, every wasted minute feels worse than usual.
- Share notes and recordings for team members who couldn't attend due to time zone conflicts. Don't make them feel excluded from important discussions.
- Be mindful of holidays. Different countries observe different holidays. Don't schedule important meetings on another country's national holiday without checking first.
- Say "your time" when proposing times. Instead of "Can we meet at 9 AM?", say "Can we meet at 9 AM your time?" This shows awareness and consideration for the other person's perspective.
- Thank people for attending off-hours meetings. A simple "I appreciate you joining early/late" goes a long way in showing respect for someone's flexibility.
Tools and Resources
TimeMeet — Visual Meeting Planner
TimeMeet is a free, privacy-first world clock meeting planner. Compare up to 6 cities with a color-coded timetable, export to your calendar, and share meeting details — all without creating an account. Available in 19 languages.
Understanding the IANA Timezone Database
The IANA timezone database (often called "tz" or "zoneinfo") is the definitive source for timezone information used by most computers and smartphones worldwide. It's maintained by a community of volunteers and updated several times per year to reflect changes in timezone rules by governments around the world. TimeMeet relies on this database for accurate conversions.
Key Concepts Quick Reference
- UTC — Coordinated Universal Time, the global reference for all time zones.
- GMT — Greenwich Mean Time, practically the same as UTC but technically a time zone (UK winter time) rather than a standard.
- DST — Daylight Saving Time, the practice of advancing clocks by 1 hour during summer months in some regions.
- Offset — The difference between a local time zone and UTC, expressed as +/- hours (e.g., UTC+9 for Korea/Japan).
- IANA ID — The standard identifier for a timezone, like "America/New_York" or "Asia/Seoul".