Tiny Telegram Tools

Telegram Timezone Converter Bot: One Time, Every Members Zone

Every distributed group has the same painful exchange: someone proposes "3pm tomorrow", someone in another zone asks "3pm where?", a screenshot of a world-clock app gets pasted, and it's wrong twice a year because daylight saving moved. The information everyone needs is one conversion away, but it keeps being re-done by hand in chat.

WhenIsItBot ends the loop. Each member sets their zone once with /tz; after that, /when 3pm tomorrow in the group replies with a card showing that time converted for every zone represented in the chat, plus UTC. Daylight saving is computed live, never hardcoded, so the card is correct even across DST transitions.

It also works with zero setup: type @WhenIsItBot followed by a time in any chat and you get a one-off conversion card via inline mode — useful in chats where you can't or don't want to add a bot. This guide covers both modes, the zone formats /tz accepts, and the free-tier limits.

Steps

  1. Set your zone once with /tz. DM the bot or run /tz in a chat where it's added: /tz Europe/Warsaw. It accepts IANA names (America/New_York), common abbreviations (CET, PST, IST, JST...), and raw offsets like +2 or -5:30. This is a one-time setup per account — every later conversion uses it.
  2. Convert for the whole group with /when. In a group with the bot added, run /when 3pm tomorrow. The card shows that time in every distinct zone set by members who've run /tz, plus UTC — deduped, up to 12 zones. The time you type is interpreted in your own zone, so "3pm" means 3pm where you are, and everyone sees their local equivalent.
  3. Convert without adding the bot (inline mode). Type @WhenIsItBot 3pm tomorrow in any chat's message box. A one-off card appears showing your zone, UTC, and a small default set (New York, London, Tokyo). No bot in the group, no permissions, works in DMs and channels where you can post. Pro users see their own saved presets in the inline result instead of the defaults.
  4. Check the current time everywhere with /now. Run /now in a group for the current time in every member zone plus UTC — handy for a quick "is everyone awake right now?" check before pinging. In a DM with the bot it shows just your own zone.
  5. Save recurring zones with /preset. If you regularly coordinate with people in Tokyo and Warsaw, save them: /preset add Asia/Tokyo. Free accounts get 3 presets. Presets shine on Pro, where inline results pull from your saved presets instead of the default zone set.
  6. Pro: /team zone sets for the whole group. Pro (one-time 150 Stars, per user) adds /team add core Europe/Warsaw America/New_York — a named, shareable zone set the whole group can reuse, plus unlimited presets. For a single-team chat, the free tier with per-member /tz already covers the core /when workflow.

Good to know

See WhenIsItBot Open in the hub

FAQ

How do I convert a time to everyone's timezone in a Telegram group?
Each member runs /tz once to save their zone. Then /when 3pm tomorrow posts a card with that time converted for every zone represented in the group, plus UTC — up to 12 zones, deduped.
What timezone formats does /tz accept?
IANA names (Europe/Warsaw, America/New_York), common abbreviations (UTC, GMT, CET, EST, PST, IST, JST, AEST, and more), or an offset like +2 or -5:30.
Can I use a timezone converter without adding a bot to the group?
Yes. Type @WhenIsItBot followed by a time (e.g. "3pm tomorrow") in any chat for an inline one-off conversion card. For group-wide per-member conversions, add the bot and use /when.
Is daylight saving handled correctly?
Yes — DST offsets are computed live at the moment of each conversion via the Intl API, so cards stay correct across transitions rather than relying on stored, hardcoded offsets.

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