How to Schedule Across Time Zones — Rules, Tools and Mistakes to Avoid

Step-by-step: send a timezone-safe meeting invite

1. Open our meeting planner. Add every city where an attendee is located — not just the organizer's city.
2. Set the date. Note: check whether the date falls near a DST transition. Our tool highlights this automatically.
3. Look at the overlap grid. Find a row where all cells are in the "business hours" range (8 AM–7 PM local time for each attendee is a reasonable band).
4. Pick the UTC time for the slot. Example: "14:00 UTC on 12 June 2026".
5. In the meeting invite title or description, write the UTC time explicitly: "Weekly sync — 14:00 UTC (10 AM New York / 3 PM London / 7:30 PM Mumbai)".
6. Send the invite with the IANA time zone set to the organizer's zone. Modern calendar apps (Google Calendar, Outlook) will automatically convert to each recipient's local time zone — but the UTC note in the body eliminates any doubt.

How to write an unambiguous time in any medium

Emails, Slack messages, and documents often need a clear time reference that does not depend on the reader being in the same zone as the writer. The ISO 8601 format with a UTC offset is the gold standard.

When writing for a known audience, listing the 2–3 most relevant local times alongside the UTC time removes any need for the reader to convert. For an audience in unknown locations, UTC alone is sufficient — anyone can convert from UTC with basic lookup tools.

The DST transition mistake and how to avoid it

Twice a year, the US and EU switch clocks on different dates. During those 1–3 week windows, the offset between New York and London is 4 hours instead of the usual 5, and the offset between New York and Paris is 5 hours instead of 6. Any recurring meeting with a hard-coded "every Thursday at 3 PM EST" rule will appear at the wrong time for European attendees during these windows.

• In Google Calendar: Always create events using the IANA zone name (shown as a city name in the time zone picker). A recurring event set to "3 PM Eastern Time" will automatically adjust for EDT in summer — you never need to manually update it.
• In Outlook: Same principle — select a time zone from the dropdown (which uses IANA names internally). Do not type the offset manually.
• In email or Slack: Write both the UTC time and the local times. The UTC time is invariant; the local times clarify what it means for each person right now. If a transition happens, the UTC anchor is still correct.
• In API calls: Always send ISO 8601 timestamps with a Z or explicit offset: 2026-06-12T15:00:00Z. Never send bare times like 15:00:00 without a timezone qualifier.

Scheduling templates for common team patterns

Rather than reinventing the wheel for every meeting, establish a set of fixed recurring slots that your team can rely on:

• US–Europe weekly sync: Every Tuesday, 14:00 UTC (10 AM EST / 3 PM CET). Works year-round regardless of DST transitions because both sides shift together in the same UTC slot.
• Europe–India daily standup: Every workday, 07:30 UTC (8:30 AM CET / 1 PM IST). CET morning meets IST afternoon; works in winter and summer because India has no DST.
• US–India fortnightly: Every other Wednesday, 14:30 UTC (10:30 AM EST / 8 PM IST). Acceptable evening for India, comfortable morning for New York.
• US–Australia quarterly: Once per quarter, 21:00 UTC (5 PM EST / 8 AM AEDT next day). One party takes an inconvenient time; rotate the role each quarter.

Defining slots in UTC makes them stable across calendar years and DST changes. Each participant's calendar software shows the correct local time automatically.