How Timehint reads times, time zones and daylight saving
Setup in three steps, the formats Timehint recognizes, how ambiguous abbreviations and daylight saving are handled, and what the extension reads and stores.
On this page
Everything Timehint shows you rests on one question: what moment does this text actually mean? "5pm IST" is not a time until you know which IST, and on which date. This page explains how a time zone extension reads abbreviations, city names and offsets, what it does when the answer is genuinely unclear, and what it reads and stores along the way.
Setting up, in three steps
Setup takes a few minutes, and most of that is saving the people you email most.
1. Install Timehint and say where you're based
Timehint runs in Chrome and Brave on desktop, version 114 or later. When you install it, Gmail tabs you already have open reload so it can work in them. Click the toolbar icon to open the side panel. The first screen asks Where are you based? and offers the city it read from your computer's clock settings. No location permission is involved. Confirm with one click, or search for a different city.
2. Save the people you work with
Add people in the side panel with a name, an email address and a time zone. Or wait for their next message in Gmail and use the Add timezone prompt, which may already have a zone ready for you to confirm. Cities you care about without a person attached go in the same list as places.
3. Read and write email with their time beside yours
Messages from saved contacts carry their local time and the time they sent. Times written with a zone in the mail you receive get your time beside them. When you type a time in a zone that isn't your recipient's, Timehint offers theirs. When you need to meet, the timeline shows when you overlap.
What counts as a time
Timehint recognizes times written the way people write them, not the way a form would demand them:
| Written as | Example |
|---|---|
| 12-hour, with or without minutes | "5pm IST", "5:30 PM EST" |
| 24-hour | "17:00 CET" |
| Military style | "1700 hrs IST" |
| Noon and midnight | "noon in Singapore" |
| A full zone name | "3pm Pacific Time" |
| A city or country | "5pm in Mumbai" |
| A UTC or GMT offset | "UTC+5:30" |
Behind that are over 120 time zone abbreviations, hundreds of city, country and region names, full names such as "Indian Standard Time", and every IANA time zone identifier your browser knows. The full pattern list is in how Timehint recognizes time zones.
The important part is what happens next. A match isn't kept as an offset; it's resolved to a real time zone, such as Asia/Kolkata or America/Los_Angeles. Everything downstream (the chip, the converted time, the timeline) asks that zone what its offset was on the date in question.
How a time zone extension reads abbreviations
Abbreviations are the hard part, because several of them name more than one place and a message almost never says which one it means. IST is India, Ireland and Israel. CST is Chicago and China. BST is Britain and Bangladesh. GST is the Gulf and South Georgia.
Guessing from context would be a coin flip dressed up as intelligence, so Timehint doesn't: each ambiguous abbreviation has one stated default, and the defaults don't change.
| Abbreviation | Timehint reads it as | To mean something else, write |
|---|---|---|
| IST | India Standard Time (UTC+5:30) | "Irish Standard Time", "Israel Standard Time", or a city |
| CST | US Central Time, as observed in Chicago | "China Standard Time", or "3pm in Shanghai" |
| BST | British Summer Time (UTC+1) | A city, such as "3pm in Dhaka" |
| GST | Gulf Standard Time (UTC+4) | A city, such as "3pm in Dubai" |
Full names and city names are exact, which is why they're the better thing to write. There's no setting for these defaults in this version, and the abbreviations article explains where each collision comes from.
Daylight saving time, resolved by date
Because a match becomes a zone rather than a fixed offset, daylight saving time needs no setting and no maintenance. "3pm Pacific Time" is PDT, UTC−7, on a date in July and PST, UTC−8, on a date in January: the same words, two different moments, decided by the date.
It also means the gap between two cities isn't a constant you can memorize. In 2026, US clocks go back on November 1 and UK clocks on October 25, so in the week between them New York is four hours behind London instead of the usual five. A 9:00 AM meeting in New York is 2:00 PM in London on Tuesday, October 20, and 1:00 PM on Tuesday, October 27.
The side panel, the sender chip and converted times in the mail you receive all follow each zone's rules for the relevant date. One feature doesn't: Use their time converts with today's offsets, so double-check a time you write for a date on the far side of a clock change.
Where Timehint says nothing
A tool that answers every question is a tool that's sometimes confidently wrong. Timehint is deliberately silent in four situations:
- A time with no zone. "Let's meet at 5" is left exactly as written. Only the person who wrote it knows which 5 they meant.
- A sender you haven't saved. No chip and no guessed zone, just an Add timezone prompt instead, which you confirm.
- Recipients in several zones. The compose chip stays quiet, because there's no single correct conversion for a group.
- A time already in your own zone. Nothing is added; you can already read it.
What Timehint reads and stores
Timehint works on your email, so it should be plain about what it touches.
- No account needed. Install it, confirm where you're based, and start. A free account is optional: it backs up your contacts and keeps them in sync across your browsers.
- Your contacts are kept in this browser. They're in the extension's local storage, in this browser profile. If you sign in, Timehint also copies them to your account. Download your contacts in Settings saves a copy as a file.
- Your email isn't sent anywhere. Timehint reads times and sender details in the messages you open, inside your browser.
- Your time zone comes from your computer's clock. No location permission is needed.
- Gmail and Google Calendar are the only websites it asks to access. The extension requests storage and side panel permissions, plus identity when it offers Continue with Google (it only opens Google's sign-in window), and access to mail.google.com and calendar.google.com.
- Settings and places can follow your browser's sync. Your settings, home time zone and saved places live in Chrome's built-in storage sync, which Chrome may copy to other browsers you're signed in to. Without a Timehint account, saved contacts stay on this device. With one, your contacts, places and a few settings sync through your account; the privacy policy lists exactly what.
The full inventory of what's stored, where, and how to remove it is in the privacy model. The waitlist on this website and the optional account are covered by the privacy policy.
Frequently asked questions
No. Every abbreviation, name and city resolves to a real time zone, and the offset comes from that zone on the date being converted. The exception is Use their time, which converts with today's offsets.
Because one of the three has to be the default, and a stated default you can look up beats a guess you can't. Write "Irish Standard Time", "Israel Standard Time" or a city when you mean one of the others.
Nothing. It isn't converted and isn't marked. Timehint doesn't assume it's in your zone or the sender's.
No. Times and sender details are read inside your browser, in the page itself. What it keeps (contacts, dismissed senders, settings) is listed above and in the privacy model. If you sign in to an account, your saved contacts, places and a few settings sync to it, but never the text of your emails.
It's built for Chrome and Brave on desktop, version 114 or later. Other Chromium browsers may work, but they aren't tested or supported, and there's no mobile version.
Next: all Timehint features, or the step-by-step guide to using Timehint.