How to use Unichrono

Getting started

Two minutes from install to a live widget.

1. Open the app. Your own city is added on first launch, so the list is never empty. A short tour explains the main ideas, and you can replay it from Settings.
2. Add the places you care about. Tap +, search by city or country, tap a result. There are 34,804 cities, ranked so the big ones come first.
3. Rename them. Open a city and rename it: Mom, NYC office, Standup. Your name is what the app, the widgets and the alerts use.
4. Put a widget on the home screen. On Android: long-press an empty spot → Widgets → Unichrono, or use the in-app widget gallery. On iPhone: long-press the home screen → + → search Unichrono.
5. Set that widget up. Pick its cities, format and colours. From then on it keeps itself correct with no further input.

Your city list

The main screen. One card per place, live, in whatever order you want.

What each card shows

• Your label for the city, with its country flag before it (flags can be turned off).
• The current time there, 12- or 24-hour, with seconds if you switch them on.
• A part-of-day icon — morning, day, evening or night — on fixed local hours, so it reads the same on every phone.
• The context line: zone abbreviation and UTC offset (for example IST · UTC+5:30), how far ahead or behind your own phone it is, and whether that city is on Yesterday, Today or Tomorrow relative to you.

Managing the list

City details

Tap any city to open its detail sheet.

• Country and time zone, with the current UTC offset.
• The local date in that city right now.
• Sunrise and sunset, calculated on the device from the city's coordinates. Change the date to check another day. Far north or south, where the sun does not rise or set at all, it says so rather than inventing a time.
• Currency and international dialling code — handy before a call or a transfer.
• Buttons that open the planner already anchored to that city.
• Rename, to give the city your own name.

Time travel

Answer "what time is it there when it's 4pm here" without arithmetic.

1. Open the ruler. Tap Time travel on the main screen.
2. Slide it. Every card re-bases to that moment at once, day labels included, so you can see who is already on tomorrow.
3. Jump to another date if the meeting is not today — the range runs about a hundred years either way, and daylight saving is applied for the date you land on.
4. Act on the moment. Hand the selected instant straight to an alarm or a meeting.
5. Close it to snap every card back to now.

Nothing you do in time travel changes your list or your widgets. It is a view, not an edit.

Alarms and meetings

One instant, every city, then turn it into something real.

The plan icon in the top bar asks whether you are setting an alarm or a meeting, then opens that board.

How the board works

• Every city you keep is listed at the same moment in time. Change the time in any row and the others follow, so you can think in whichever city you think in.
• The row you edit becomes the anchor and is badged as such.
• Pick the time with the wheel or the dial, and move the whole board to another date.
• Add a city just for this board when you need to check somewhere that is not in your list.
• Availability dots mark who the slot lands badly for, so you see the 6 a.m. victim before you send the invite.

Alarm

Pick the time in any city and set the alarm. On Android, your phone's own clock app receives the matching local time. On iPhone, the alarm is scheduled with Apple's AlarmKit (iOS 26.1 or later) and rings on your device.

Meeting

• Add to calendar creates an event at that instant. On iPhone this uses Apple's write-only calendar access — the app can add the event you asked for and cannot read anything in your calendar.
• Share invite builds a text block listing the time in every city on the board, ready for chat or email.
• Alert me in this city turns the slot into a city alert.
• Label is optional and rides along into the event and the shared text.

City alerts

Be told when a chosen time arrives somewhere else.

1. Open Alerts (the bell) and add one.
2. Choose a city — from your list or from the full search.
3. Pick the time in that city's local clock, and give it a label such as Remind Mom about Medicine.
4. Choose the repeat: once on a date, every day, or the weekdays you select.
5. Choose how it arrives: a silent notification, or spoken aloud with a buzz.

The row then shows the city, the time there, the repeat, and what that works out to in your own time. Alerts are rescheduled automatically after a reboot.

Announce the time

Your own local time, said out loud, hands-free.

• Hourly announces on the hour, inside a window you set — a first hour it may speak and an hour from which it stays quiet. Set both the same to announce all day.
• Daily announces once, at the one time you choose.
• Try it plays a sample immediately so you can hear the voice before committing.
• Announcements respect the ringer: silenced means vibrate only, Do Not Disturb means silence.

This speaks your own device time. To be told about a time in another city, use a city alert instead.

Widgets

The main reason the app exists.

Why they never freeze

Most world-clock widgets redraw the time from a background job, which battery optimisation, Doze and OEM task killers eventually shut down — which is why competing widgets stop at some stale time. Unichrono runs nothing in the background to keep time. Each clock ticks straight from the system clock with its own timezone attached, so it stays live and correct with no process of ours running, and it costs no battery.

Android

• Add: long-press an empty part of the home screen → Widgets → scroll to Unichrono. Or open the in-app widget gallery, swipe through the styles and let it ask the launcher to place one.
• Set up: the setup screen opens as soon as the widget lands. Everything you choose applies to that one widget.
• Change it later: tap the widget — its setup screen reopens with the current cities and colours.
• Resize: long-press it and drag the handles. More space means more rows and more detail; less space means the widget shrinks its text and, if it must, shows a +N more footer rather than clipping a city.
• Remove: drag it to Remove. Its settings go with it; your city list is untouched.

iPhone & iPad

• Add to the Home Screen: long-press the wallpaper → + (top left) → search Unichrono → pick a widget and size → Add Widget.
• Add to the Lock Screen: long-press the Lock Screen → Customise → tap the area under the clock → choose a Unichrono accessory.
• Set up: long-press a placed widget → Edit Widget, then choose its cities and options.
• Browse first: the in-app widget gallery previews every style with live data. iOS does not let an app place a widget for you, so the gallery shows you what to look for and where.
• Remove: long-press → Remove Widget.

The widget types

Each is a separate widget with its own setup.

Availability, in detail

• Work window — 9:00 to 17:00 by default, in each city's own local time, in 30-minute steps. Overnight windows are fine.
• Shoulder — the amber edge either side, 1 hour by default.
• Work days — Monday to Friday by default, any set you like.

Widget setup options

What a widget's own setup offers, and how it relates to the app's settings.

Everything on a setup screen applies to that widget alone. Two World Clock widgets can hold different cities, formats and colours, and changing a setting in the app does not rewrite widgets you already placed.

Names on widgets

A widget snapshots the city names as they were when you set it up, so renaming a city in the app later does not silently rewrite a widget you were happy with. To change a widget's labels, edit them in that widget's setup.

Long names are shortened intelligently rather than chopped, so two cities on a small widget never end up looking identical.

Android — where every setting lives

Open the app → the gear icon. In the order you meet them.

Clocks in the notification shade

1. Turn on Clocks in notification. On Android 13+ you are asked for notification permission once.
2. Pull down the shade from anywhere — your cities are there, ticking live, with your labels and format.
3. Tap it to jump into the app. Swipe it away when you are done; dismissing it is respected rather than undone.

It is optional, off by default, and ticks from the system clock, so it costs nothing to leave on.

The Quick Settings tile

Pull the shade down fully, edit your tiles, and drag Unichrono in for a fast glance and a one-tap way back into the app.

Keeping it reliable

Widgets and the notification work with no setup on most phones. Some manufacturers restrict apps aggressively, which can remove the ongoing notification or stop it reappearing after a reboot. If that happens, allow Unichrono to run in the background — wording differs by phone:

• Settings → Apps → Special app access → Background power management → Unichrono → Don't restrict
• Battery settings for Unichrono → Unrestricted
• Battery optimisation list → Unichrono → Don't optimise

Protect the notification in Settings detects your phone's flavour and opens the right page where it can.

iPhone & iPad — where every setting lives

Open the app → the gear icon. Widget appearance lives on the widget itself.

Widget appearance on iPhone

iOS draws the widget's options itself: long-press a placed widget → Edit Widget. Cities, colour, time format and the rest are chosen there, per widget.

Permissions, and when they are asked

Nothing is requested at launch. Each of these is asked only the first time you use that feature, and declining one leaves the rest of the app working normally.

Spoken alerts use the system's built-in voice. That needs no permission, records nothing, and never touches the microphone.

Lock Screen accessories

Long-press the Lock Screen → Customise → tap the area under the clock → add a Unichrono accessory. Long-press a placed accessory to choose which city it shows.

Troubleshooting

My widget shows the wrong time

Unichrono reads your phone's clock and applies each city's timezone rules from the database the OS ships. If every city is off by the same amount, the phone's own clock is wrong — turn on automatic date and time. If one city looks wrong right around a daylight-saving change, install the latest system update, since the timezone rules come with it.

The launcher says "Couldn't add widget" (Android)

Some launchers refuse a widget dropped onto a spot too small for it. Free up a bigger area and try again, or add it from the in-app widget gallery, which asks the launcher to place it for you.

My widget lost a city, or shows "+2 more"

It ran out of room. The widget shrinks its text first and only then hides the overflow, so the cities you do see are never clipped. Make it wider or taller, or switch its row detail to Compact.

The clocks notification disappeared (Android)

Almost always the phone's battery manager removed it. See Keeping it reliable. Re-enabling it brings it back immediately.

My alerts arrive a few minutes late (Android)

Exact alarms are not permitted for the app. Open the alerts screen and tap Allow exact alarms; the banner disappears once granted.

An alert stayed silent

Check that notifications are allowed for Unichrono, and that the phone is not silenced or in Do Not Disturb / a Focus. Spoken alerts deliberately only vibrate when the ringer is off.

"Set alarm" is greyed out (Android)

Android's alarm handoff carries an hour and a minute but no date, so it always means the next time that hour comes round. When the moment you picked would ring on the wrong day, Unichrono disables the button instead of setting a misleading alarm. Use a calendar event or a city alert.

I can't set an alarm on my iPhone

Scheduled alarms use Apple's AlarmKit, which needs iOS 26.1 or later. On older versions, use a calendar event or a city alert instead.

Renaming a city did not change my widget

That is intentional — widgets keep their own labels so an in-app rename cannot rewrite a widget you already set up. Edit the labels in that widget's own setup.

The Analog widget is not available on my phone

It needs Android 12 or newer. Below that, Android cannot give an analog face its own timezone, so it could only ever show your local time.

Privacy and data

• On Android the app has no network permission. It cannot send anything anywhere, and the city data ships inside the app rather than being fetched.
• No accounts, no ads, no analytics, no tracking SDKs, on either platform.
• Your cities, labels, widget settings and alerts are stored on the device only, and go when the app goes.
• The permissions it does ask for are the obvious ones, requested only when you first use the feature that needs them.
• City data comes from GeoNames.org, licensed CC BY 4.0.

Full details are in the privacy policy.

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