About Timehint
Why Timehint exists, the principles that shape it, what it stores and where, and how it recognizes time zones in the emails you read and write.
Timehint is a Chrome and Brave extension that handles time zones for Gmail users, inside Gmail, in Google Calendar and in the browser side panel. It shows the local time of the people you work with right next to them, where you read and write email. This page is about Timehint: why it exists, the principles behind its design, exactly what it stores and where, and how it recognizes a time zone when someone writes one. Timehint is built and supported by the Timehint team.
Why Timehint exists
Most time zone mistakes don't happen in a planning tool. They happen in email, in a sentence someone typed quickly.
A client in Chicago writes "Can we do 3 PM?" and you stop to work out whose 3 PM. You're in New York, and a reply from a colleague in Bengaluru arrives at 1:40 PM. For her it was 11:10 PM, the end of a long day, and nothing on the screen says so. A partner proposes "10am CST", and it's worth pausing: Chicago and Shanghai both use that abbreviation, and in September they're 13 hours apart. Then there's the week each autumn when the gap between New York and London is four hours instead of five, and a recurring call set in New York time starts an hour earlier than usual in London.
None of these is hard to work out. The trouble is that they come up again and again, in the middle of other work, and each one means leaving the email to look something up. A converter website can tell you what time it is in Tokyo. It doesn't know that Kenji, the person you're writing to, is in Tokyo, and it can't see the "5pm IST" you're about to send him.
Timehint exists to close that gap. The answer should sit next to the person: on their message when you read it, in your draft when you write to them, and in a panel beside your inbox when you plan. That's why Timehint lives in the browser, in Gmail and the side panel, instead of in a separate app or website you have to switch to.
What Timehint does for time zones in Gmail, and what it doesn't
Timehint does three jobs.
- A side panel of your people and places. Each row shows a live local time, how far ahead or behind you that person is, and the time of day there.
- A way to pick a time. Today in your cast puts everyone's work, fringe and off hours on one 24-hour timeline, for today or any day up to two weeks ahead. Overlap windows ranks the best stretches of shared working time.
- Help inside Gmail. A chip shows a saved sender's local time and when they sent the message. Add timezone saves a sender you haven't saved yet. A time written with a time zone in a message you receive gets your local time beside it. Use their time offers your recipient's time when you write a time in a different zone.
- Help inside Google Calendar. Open an event and each saved guest shows their local time for its start, coloured for their work, fringe or off hours. Times written with a time zone in the event's description get your local time beside them.
It's just as important to be clear about what Timehint doesn't do:
- It doesn't create events, send invitations or book meetings. It shows you when people are working. You decide what to propose.
- It doesn't change other websites. The in-page features work in Gmail and Google Calendar on the web. Everywhere else, you use the side panel.
- It doesn't save anyone's time zone without you. A sender's zone is stored only after you confirm it.
- It isn't a shared directory. Each person keeps their own contacts. The optional account syncs yours across your own browsers; it doesn't share them with anyone.
- It doesn't run on phones or tablets, or in the Gmail and Calendar mobile apps.
Timehint does fewer things on purpose. Every feature has to be right in the moments people rely on it, and a smaller product is easier to keep right. For a tour of each feature with worked examples, see what Timehint does.
Principles
These principles come from specific decisions in the product. Each one describes how Timehint behaves today, not an aspiration.
Offer, don't assume
Timehint doesn't show a converted time for a stranger based on a guess. A sender without a saved time zone gets an Add timezone prompt, not a time. Guessing a location from an email domain was deliberately removed: a .de address can belong to someone working in Lisbon, and a confident wrong answer does more harm than no answer.
Show where a suggestion came from
When Timehint does suggest a time zone, it says why. The dialog quotes the text it used, for example: Suggested from "2 pm Indonesia time" in their message. An unexplained guess sitting in a form field reads like a fact. A suggestion with its evidence is something you can check in a second. See how Add timezone works.
Change your words only when you click
Use their time offers a rewrite; it doesn't make one. Your draft changes only when you click the button, and × leaves the draft as you wrote it. When the converted time falls on another day, the chip adds "next day" or "previous day", so a date change doesn't slip past you. See how Use their time works.
Stay quiet when there's no single right answer
If you're writing to saved recipients in different time zones, there's no one time to rewrite into, so Timehint offers nothing. A time written with no time zone at all, like "let's meet at 5", is left alone, because only the writer knows which 5 they meant. And if a message names several time zones besides yours, Timehint doesn't use them to suggest the sender's zone.
Ask once, then respect the answer
Prompts shouldn't nag. Dismiss on an Add timezone chip holds that prompt back for 30 days. If you travel, Timehint asks only when the time zone you chose differs from your computer's clock. A card says, for example, "Your computer's clock is on Tokyo time" and offers Keep London or Switch to Tokyo. Choose Keep and Timehint won't ask about that zone again for 30 days. Close the card with × and it stays quiet for 7 days. See what happens when you travel.
Local first
Timehint works without an account, and your contacts are stored in your browser. An account is optional: if you sign in, it backs up your contacts and syncs them across your browsers, and signing out keeps the copy in your browser. The first-run screen, Where are you based?, reads your time zone from your computer's clock settings, so it doesn't ask for location access. You can download your contacts as a file whenever you like.
Be honest about status
Timehint is free during early access, and there are no paid plans. It isn't on the Chrome Web Store yet, so every install button on this site opens the waitlist. This site doesn't show user counts, ratings or testimonials.
Privacy model
Timehint works on your email, so you should know exactly what it reads, what it keeps and where. This section describes the extension as it's built today.
What Timehint reads
In Gmail on the web, Timehint reads what it needs from the page, inside your browser:
- the sender's name and email address on messages you open;
- the text of those messages, to find written times, signature clues and time zones the sender mentions;
- while you write, the text of your draft and your recipients' email addresses, so it can offer Use their time.
In Google Calendar on the web, it reads the event you open: its start date and time, its guests' email addresses and the text of its description.
That reading happens in the page itself. Timehint never sends your email or your drafts anywhere. Your contacts leave the browser only if you sign in to the optional account, which syncs them.
What Timehint stores, and where
| What | Where it's kept | Notes |
|---|---|---|
| Saved contacts: name, email address, time zone | This browser profile (chrome.storage.local) |
Stays on this device unless you sign in. Download a copy from Settings anytime. |
| Senders you dismissed, with the date | This browser profile | Keeps the Add timezone prompt away for 30 days |
| For saved contacts, a count of the local hours their messages were sent | This browser profile | Not shown anywhere in this version |
| Settings, your home time zone and saved places | Chrome's built-in storage sync (chrome.storage.sync) |
Chrome may copy them to other browsers where you're signed in |
| Only if you sign in: your contacts, places, home time zone, clock format and working day | Your free Timehint account, in our database | Synced to every browser where you sign in. Exactly what syncs |
Because settings and saved places sit in Chrome's storage sync, Chrome may copy them to browsers where you're signed in. Without a Timehint account, saved contacts don't sync: they stay on this device. With the optional account, Timehint syncs your contacts, places and a few settings through it, and never your email.
Permissions
The extension asks your browser for these:
| Permission | Why Timehint needs it |
|---|---|
storage |
To save your contacts, places and settings in your browser |
sidePanel |
To open the side panel from the toolbar icon |
identity |
Only in versions that offer Continue with Google: to open Google's sign-in window when you choose it |
Access to https://mail.google.com/* |
To show the sender chip, Add timezone, converted times and Use their time in Gmail |
Access to https://calendar.google.com/* |
To show each saved guest's local time on the events you open in Google Calendar |
Gmail and Google Calendar are the only websites Timehint asks to access.
What Timehint doesn't do
- It doesn't need an account. Every feature works without one; the free account only backs up and syncs your data.
- It doesn't include analytics or tracking code.
- It doesn't ask for your location. Your time zone comes from your computer's clock settings.
- It doesn't fetch fonts from a font service. The side panel's fonts are bundled inside the extension.
If you remove Timehint, your browser deletes the contacts it kept in local storage. Download a copy first if you want one; if you're signed in, your account keeps its synced copy.
This website
This website is separate from the extension. When you join the waitlist, we store the email address you enter so we can tell you when Timehint is available. The privacy policy explains what the site collects and how to have it deleted.
How Timehint recognizes time zones
This section goes into more technical detail. It explains how Timehint turns text like "5pm IST" into a precise moment, and how it suggests a sender's time zone.
Reading a written time
Timehint's parser has 26 patterns for the ways people write a time with a time zone:
| Written as | Examples |
|---|---|
| 12-hour, with or without minutes | "5pm IST", "5:30 PM EST" |
| Compact 12-hour | "530pm IST" |
| 24-hour | "17:00 CET" |
| Military style | "1700 hrs IST" |
| Noon and midnight | "noon in Singapore", "midnight GMT" |
| UTC and GMT offsets | "9am UTC+5:30" |
| ISO 8601 timestamps | "2026-09-14T15:00:00Z" |
| Full zone names | "3pm Pacific Time", "3 PM Indian Standard Time" |
| IANA identifiers | "10am Asia/Kolkata" |
| Cities and countries, before or after the time | "5pm in Mumbai", "Mumbai 5pm", "9am India time" |
To resolve the time zone part, Timehint draws on more than 120 abbreviations (129 today), more than 350 city, country and region names, and a set of full names and everyday phrasings such as "Pacific Time" and "UK time". People write both "Indian Standard Time" and "India Standard Time", so both are recognized. Timehint also accepts every IANA time zone identifier your browser supports, including modern spellings like Asia/Kolkata that some browsers list only under an older name.
Daylight saving time
Every abbreviation, name and city resolves to an IANA time zone, such as America/Los_Angeles, and the offset comes from that zone on the date in question. That's how "3pm Pacific Time" becomes PDT (UTC−7) in July and PST (UTC−8) in January. The rules come from your browser's built-in time zone data, which is based on the IANA time zone database, the widely used public record of the world's time zone rules.
Because countries change their clocks on different dates, the gap between two cities isn't fixed. In 2026, clocks in the US go forward on March 8 and back on November 1 (NIST). In the UK they change on March 29 and October 25 (GOV.UK). During the weeks in between, New York is four hours behind London instead of the usual five. Timehint follows those changes without any setting.
Abbreviations with more than one meaning
Some abbreviations name different places, and a message rarely says which one the writer meant. Timehint uses a fixed default for each, shown below. There's no setting to change these defaults, so if you mean something else, write a full name or a city instead.
| Abbreviation | Timehint reads it as | It can also mean | To be exact, write |
|---|---|---|---|
| IST | India Standard Time (UTC+5:30) | Irish Standard Time (UTC+1, Ireland's summer time); Israel Standard Time (UTC+2) | "Irish Standard Time", "Israel Standard Time" or a city |
| CST | US Central Time, as observed in Chicago on that date | China Standard Time (UTC+8) | "China Standard Time" or a city such as Shanghai |
| BST | British Summer Time (UTC+1) | Bangladesh Standard Time (UTC+6) | A city such as Dhaka |
| GST | Gulf Standard Time (UTC+4) | South Georgia Time (UTC−2) | A city such as Dubai |
The full story of these collisions, and what to write instead, is in IST, CST, BST: ambiguous time zone abbreviations explained.
No time zone, no conversion
A time without a time zone, such as "let's meet at 5" or "tomorrow at 10:30", isn't converted. Timehint doesn't assume it's in your time zone or the sender's. Only the writer knows which zone they meant, so the time is left exactly as written.
How a sender's time zone is suggested
When you click Add on an Add timezone chip, Timehint reads the open message for clues, and then the rest of the open thread if that message has none.
- Signature clues come first. Timehint looks at the last dozen or so lines of the message, ignoring any quoted reply. Each clue has a weight, and a suggestion is offered only when the evidence is strong enough:
- An explicit location phrase, "Based in", "Located in", "Writing from" or "Sent from" followed by a capitalized city, is enough on its own: "Writing from Tokyo" suggests Tokyo. A bare "from", as in "Greetings from Paris", isn't.
- A phone country code is enough on its own: "+44 20 7946 0000" suggests London. A +1 number is ignored, because that code covers the US, Canada and parts of the Caribbean, across many time zones.
- A city in a pipe-separated signature line isn't enough on its own, but together with a matching phone code it's the strongest signature clue: "Lukas Becker | Berlin | +49 30 1234567" suggests Berlin.
- A time zone the sender wrote comes later, and only when the message points to a single zone. If the sender also gives your own time as a courtesy, your zone is set aside first.
- The email domain isn't used. A company's domain says little about where one person works.
The suggestion appears in the dialog with the text it came from. You confirm it or choose another zone, and only then is the contact saved.
Early access
Timehint is in early access. In practice, that means three things:
- It's free. Every feature is free during early access, and there are no paid plans.
- It isn't on the Chrome Web Store yet. Waitlist members get an email as soon as Timehint can be installed, and some may be sent an early-access link ahead of the public launch. We send nothing beyond that, and we'll delete your address at any time on request.
- Feedback is welcome. If Timehint misreads a time or suggests the wrong zone, tell us how the time was written, with any private details removed. Examples like that make a problem much easier to fix.
Frequently asked questions about Timehint
Timehint is made by the Timehint team. You can reach us at hello.kailashsr@gmail.com, and we reply within one business day.
Email is where a lot of time zone confusion starts: a time written quickly in one place, read somewhere else, and acted on without a second look. Focusing on Gmail on the web lets Timehint put the answer exactly where that happens, on the recipient line of a message and in the draft you're writing. The side panel covers the rest of your browser.
Only inside your browser, and only for what it needs: times, time zones, signature clues and the sender's name and address. It doesn't send your email anywhere. The privacy model above lists everything Timehint stores, and the website's own data practices are in the privacy policy.
Because a wrong time zone is worse than none. A signature can name a head office rather than where someone works, and a time zone written in a message can belong to someone else in the thread. Timehint suggests what it finds and shows its evidence, but a contact is saved only when you confirm it.
If you want to keep your contacts, open Settings and use Download your contacts first. Then remove Timehint from your browser's extensions page. Chrome deletes the data an extension keeps in local storage when the extension is removed, and that's where your saved contacts live. Settings and saved places in Chrome's storage sync follow your browser's sync settings. Removing the extension doesn't delete an account: to delete your account and everything synced to it, or to remove your email address from the waitlist, write to hello.kailashsr@gmail.com.
Yes. Every feature is free during early access, and there are no paid plans.
Get in touch
Have a question, a time zone Timehint read wrong, or a privacy request? Email hello.kailashsr@gmail.com or visit the contact page. We reply within one business day. If you're setting Timehint up, the step-by-step guide covers every screen and setting.