# The Timehint blog: guides for working across time zones

> Guides for working across time zones: read a sender's local time in Gmail, write times clearly, schedule meetings and avoid daylight saving traps.

Source: https://timehint.app/blog

People working across time zones solve the same few problems again and again. An email arrives from Tokyo and you wonder whether it's too late to reply. You propose "2 PM" and someone joins an hour late, because they read it in their own time. A weekly call with London slides by an hour for one week in October, even though nobody changed it.

This blog collects practical guides for working across time zones, written for people who do most of that work in email. Each guide explains why a problem happens, then how to handle it yourself, with real city pairs and clock times you can check. You don't need to install anything to use them.

This page is the hub. It lists every guide, then walks through the four topics we cover. For each topic you'll find the key takeaways and a link to the full article, so you can go straight to the one you need.

## All guides

- **[How to see a sender's time zone and local time in Gmail](https://timehint.app/blog/see-someones-local-time-in-gmail)**: Gmail stamps every message with your time, not the sender's. How to find someone's local time, read when they really wrote, and avoid daylight saving and date-line mistakes.
- **[How to write time zones in an email so nobody misreads them](https://timehint.app/blog/how-to-write-time-zones-in-email)**: a format for meeting times nobody can misread: time, zone and date, the reader's time first, safe abbreviations, midnight rules, templates and a checklist.
- **[How to schedule meetings across time zones: a practical guide](https://timehint.app/blog/schedule-meetings-across-time-zones)**: find the real overlap in everyone's working day, choose a fair slot, rotate the hard ones and plan for the 2026 daylight saving weeks, with verified windows for common city pairs.
- **[IST, CST, BST: ambiguous time zone abbreviations explained](https://timehint.app/blog/ambiguous-time-zone-abbreviations)**: IST, CST, BST and GST each stand for more than one place. What every reading means, with verified offsets and 2026 daylight saving dates, and a style guide for writing times nobody can misread.
- **[US and Europe daylight saving out of sync: what the 2026 clock changes do to your meetings](https://timehint.app/blog/us-europe-daylight-saving-mismatch)**: from October 25 to November 1, 2026, and from March 8 to 29, US and European clocks are out of sync. The verified dates, what changes for common city pairs, and a checklist for recurring meetings.

## Four problems that come up when working across time zones

Most time zone mistakes come from one of four gaps. Naming them makes it easier to see which guide you need.

1. **Reading: you see when a message arrived, not what their clock said.** Priya in Bengaluru opens a reply from Kenji at 8:30 AM. For Kenji in Tokyo, it's noon. Whether that reply was quick or written late at night depends entirely on his clock, not hers.
2. **Writing: a time needs a zone, and a zone needs a date.** "Let's talk at 2" means different things in every inbox that receives it. Even "9 AM ET" only becomes precise with a date. On Tuesday, November 3, 2026, it's 2:00 PM in London, 7:30 PM in Bengaluru, 11:00 PM in Tokyo and 1:00 AM on Wednesday in Sydney.
3. **Scheduling: shared working hours are smaller than they look.** New York and London share about three hours of a 9-to-5 day. London and Sydney share none. Finding a fair slot is a real decision, not a lookup.
4. **The calendar moves under you.** Daylight saving starts and ends on different dates in different countries, and abbreviations like IST and CST name more than one place. From October 26 to 30, 2026, a 9:00 AM New York call is at 1:00 PM in London, not 2:00 PM.

The sections below take each problem in turn.

## Reading a sender's local time in Gmail

When someone emails you from another country, two questions matter. What time is it for them now? And what time was it when they wrote? The answers change how you read a message and when you reply. A two-line note sent at 11:40 PM their time says something different from the same note sent at 9:00 AM.

The time next to a message tells you when it was sent, shown in your time zone. To get to the sender's local time, you need to know, or work out, where they are. Our guide covers the practical ways to do that:

- **Look for clues the sender gives you.** A city in their signature, a phone number with a country code, or a phrase like "2 pm Indonesia time" usually tells you more than anything else.
- **Don't treat an offset as a place.** UTC−5 is New York in winter, Chicago in summer, and Bogotá all year. An offset tells you the clock at one moment, not where someone is or what their clock will say next month.
- **Convert the sent time into their zone.** A reply that lands at the start of your morning may have been written at the end of their day. That's useful context for tone and urgency.
- **Check their "now" before you reply or call.** Look at their local time and whether it's a working day for them. Working days and public holidays differ between countries.
- **Save it once.** For people you email every week, note their time zone somewhere you'll see it, so you don't repeat the detective work.

Daylight saving weeks and the date line trip up even careful readers, because the difference you remember may not apply on the day the message was sent. The guide covers both.

Read the full guide: [how to see a sender's time zone and local time in Gmail](https://timehint.app/blog/see-someones-local-time-in-gmail).

## Writing times in email

Writing a meeting time is the one time zone task that you fully control. A format that can't be misread prevents most of the problems on this page.

- **Give the reader three things:** the time, the time zone and the date. The date matters because daylight saving changes the difference between two cities, and because many international times cross midnight.
- **Put the reader's time first,** with yours in brackets. It saves them the conversion, and it shows you've done the work.
- **Write ET when you're not sure whether it's EST or EDT.** In 2026, New York is on EDT from March 8 to November 1, so "EST" in July is technically an hour off. "ET" or "New York time" is right all year. The same applies to CT and PT.
- **Prefer city names to abbreviations.** "3:00 PM Dublin time" can't be confused with India. "3:00 PM IST" can.
- **Be careful around midnight.** "12:00 AM on Friday" is read two ways. For deadlines, "11:59 PM on Thursday" or "end of Thursday, London time" is safer.
- **When a group spans several zones, list each city.** "Tuesday, November 3: 9:00 AM New York, 2:00 PM London, 7:30 PM Bengaluru" is longer, but no one has to guess.

The guide also covers the reverse problem: converting a time someone sent you. If a colleague writes "EST" in July, they usually mean Eastern Time as observed that day, so confirm before you convert literally. It includes signature formats that stay correct through daylight saving, and copy-paste templates for proposing, confirming and rescheduling.

Read the full guide: [how to write time zones in an email so nobody misreads them](https://timehint.app/blog/how-to-write-time-zones-in-email).

## Scheduling meetings across time zones

Scheduling is where time zones cost the most, because a bad slot repeats every week. The guide starts from working hours, not from time zones. Everyone's day has a start and an end, and a "9 to 6" assumption hides early starters, school runs and people who work late by choice.

The core method is simple: put everyone on one 24-hour line in half-hour steps, mark each person's working hours, and look for the stretch they share. Here's what that shows for some common pairs, assuming 9:00 AM to 5:00 PM on both sides:

| Pair | Shared working time | When |
|---|---|---|
| New York and London | 3 hours | 9:00 AM–noon New York (2:00–5:00 PM London) |
| Chicago and Berlin | 1 hour | 9:00–10:00 AM Chicago (4:00–5:00 PM Berlin) |
| London and Bengaluru | 2½ hours in January, 3½ in July | Mornings in London, afternoons in Bengaluru |
| San Francisco and London | None | No shared hours |
| New York and Sydney | None | No shared hours |
| London and Sydney | None | No shared hours |

These windows move when clocks change, which is why the guide gives dates for every example.

When there's no overlap, you have three honest options:

- **Stretch one side,** but rotate who stretches if the meeting repeats.
- **Split the meeting** into two sessions, one for each region.
- **Replace it** with a written update and a shorter live call.

The guide explains how to choose the best slot when several are possible, weighing how many people are in working hours, how long the window is, and how civil the hour is. It also shows how to rotate the inconvenient slot fairly when a meeting repeats.

Read the full guide: [how to schedule meetings across time zones](https://timehint.app/blog/schedule-meetings-across-time-zones).

## Time zone abbreviations and daylight saving

The last topic is the one that makes careful people look careless. Time zone abbreviations aren't an international standard. They're conventions, and several are reused for completely different places. The time zone database that computers rely on names zones by region and city instead, such as `Asia/Kolkata` and `America/Chicago`.

The abbreviations that cause the most trouble in email:

| Abbreviation | Can mean | Offset |
|---|---|---|
| IST | India Standard Time | UTC+5:30 |
| IST | Irish Standard Time (Ireland in summer) | UTC+1 |
| IST | Israel Standard Time (winter) | UTC+2 |
| CST | Central Standard Time (US, winter) | UTC−6 |
| CST | China Standard Time | UTC+8 |
| BST | British Summer Time | UTC+1 |

A "CST" mix-up between Chicago and Shanghai is a 14-hour mistake in winter. Our abbreviations guide explains how to tell which meaning a writer intended from context, and what to write instead: a city name, or a UTC offset for that date.

Daylight saving adds a second layer. In 2026:

- **US and Canada** move forward on March 8 and back on November 1.
- **The UK and the EU** move on March 29 and October 25.
- **New Zealand** moves back on April 5 and forward on September 27. **Sydney** moves back on April 5 and forward on October 4.
- **India and Singapore** don't change at all.

Because those dates don't line up, the usual difference between two cities is wrong for a few weeks each year. New York and London are four hours apart, not five, from March 8 to 29 and from October 25 to November 1. Our seasonal guide lists what changes for common pairs and gives a checklist for recurring meetings, with the dates for 2026 and 2027.

Read the full guides: [IST, CST, BST: ambiguous time zone abbreviations explained](https://timehint.app/blog/ambiguous-time-zone-abbreviations) and [US and Europe daylight saving out of sync](https://timehint.app/blog/us-europe-daylight-saving-mismatch).

## How we write these guides

Time zone advice is only useful if it's right on the date you need it. These are the rules we hold every guide to:

- **Every time and offset is checked with code.** Conversions are computed from the IANA time zone database for the specific date in the example, not from a rule of thumb.
- **Rules come from primary sources.** Daylight saving dates are checked against the official sources: NIST for the US, GOV.UK for the UK, Directive 2000/84/EC for the EU, and the Australian and New Zealand government pages. Guides link the sources they rely on.
- **Every guide is dated.** You'll see when it was published and when it was last updated. Guides tied to the clock changes are revised in place each season, at the same address.
- **Examples are realistic but fictional.** The people in our examples, like Priya in Bengaluru or Sarah in New York, are invented. The cities and clock times are real.
- **No invented numbers.** If a guide cites a figure, it links to where the figure comes from.
- **Useful without our product.** Every guide teaches a method you can use by hand. Where Timehint helps, the article says so in a clearly labeled "How Timehint helps" box.

If you spot a mistake, or a time zone question we haven't answered, email [hello.kailashsr@gmail.com](mailto:hello.kailashsr@gmail.com). We reply within one business day, and we correct guides openly by updating the date.

Timehint is a Chrome extension that keeps the local time of the people you email in a side panel and in Gmail. It's free during early access, and it isn't on the Chrome Web Store yet: join the waitlist and we'll email you when you can install it.