World Clock · iPhone
ZoneTime lines up every city on one swipeable timeline, color-coded by work, awake, and night hours — so you always know the right moment to reach out. Plan a meeting in seconds and share it by calendar, email, or text.
Inside the app
A synced timeline, one-tap meeting planning, and instant offline search across 7,000+ cities.
← swipe or scroll to explore every screen →
Key features
Six ways ZoneTime keeps every city's schedule in view.
Have a question about using ZoneTime? Start here — if you don't see your answer, email us and we'll help.
Email us and include your iPhone model and iOS version if you're reporting a bug — we read every message.
Email support →Last updated: August 25, 2026. This policy applies to the ZoneTime iOS application published by Mark Utility Labs.
Short version: ZoneTime stores your groups, locations and settings only on your iPhone, and none of it is ever sent off your device. What does leave the app is anonymous and technical: a crash report when the app crashes, and a count of how the unlock screen is used. No ads, no advertising identifiers, no tracking you across other apps or websites, and no sale of your data, ever.
ZoneTime saves the groups you create, the locations inside them, any custom labels you add, your chosen home city, and your app settings — time format, theme, default meeting length, and which highlights show on the timeline.
All of this is stored locally on your device using on-device storage (AsyncStorage). It never leaves your iPhone, and no account or sign-in is needed to use the app. Deleting a group or location removes it immediately; uninstalling the app removes everything.
ZoneTime uses Firebase Crashlytics, a service run by Google, to report crashes automatically so bugs get found and fixed. When the app crashes, a report goes to Google containing the device model, the iOS and app version, the technical details of the crash, and a random identifier Firebase generates for your installation of the app. That identifier is not your name, your email, or your Apple ID; delete and reinstall the app and it changes. A crash report never contains your groups, your locations, your labels or your settings.
When ZoneTime shows its unlock screen, it counts a short list of events through Firebase Analytics, also from Google: that the screen was shown, which layout was shown, and that an unlock completed. These events carry no personal content — none of your groups, your locations, your labels or your settings, no name, no contact details. ZoneTime never attaches your identity to them; Firebase records them against the same kind of per-install identifier described above. They exist so we can tell whether the unlock screen works, and for nothing else.
Apple handles the transaction itself. Mark Utility Labs never sees or stores your card details, billing address, or Apple ID password.
Your unlock is kept on your device, in the iOS Keychain. If you unlock the whole collection of Mark Utility Labs apps at once, ZoneTime offers to safeguard that unlock so you can get it back on a new device — the only feature in the app that involves signing in anywhere. Only if you choose it, ZoneTime asks you to Sign in with Apple and stores a short record in Google Firestore, keyed to the identifier Apple returns: which unlock you hold and when you got it. Nothing else goes into it. ZoneTime never asks Apple for your name or email address, so we hold no way to connect that record to a real-world identity — but because it is keyed to your Apple sign-in it is a per-person record, and Apple's privacy labels for ZoneTime declare it as linked to you.
It's worth being explicit about the absences:
Google (Firebase) receives crash reports, the anonymous usage counts, and — only if you choose to safeguard an unlock — the unlock record. Apple handles the transaction and Sign in with Apple. There are no other recipients.
ZoneTime can request one system permission: Calendar, write-only. It's requested the moment you tap "add to calendar" on a meeting, solely so that event can be added to your calendar. ZoneTime never reads your existing calendar events.
ZoneTime is not directed at children under 13 and does not knowingly collect personal information from children. It never asks anyone, of any age, for a name, an email address, or any other identifying detail.
If this policy changes, we'll update the "Last updated" date above. Continued use of ZoneTime after a change means you accept the updated policy.
Questions about this policy or your privacy? Please contact us at:
Mark Utility Labs
Email: mark@vibecode.review
Last updated: August 1, 2026. These terms cover the ZoneTime iOS application published by Mark Utility Labs.
Short version: ZoneTime runs on your device, needs no account, and shows you no ads. Use it however you like; just double-check anything critical.
ZoneTime is published by Mark Utility Labs for your personal use. It needs no account and no sign-up, it shows no advertisements, and your cities and groups stay on your device.
Some features are unlocked by an in-app purchase. Any purchase is a one-time, non-consumable unlock — there is no subscription, nothing renews, and you are not charged again for what you have already unlocked. Purchases are processed by Apple through the App Store rather than by Mark Utility Labs, and refunds are handled by Apple under its standard App Store refund process at reportaproblem.apple.com.
ZoneTime converts times using the standard IANA time zone database, including daylight-saving rules. Those rules change, and software can contain mistakes. For anything critical — flights, interviews, court dates, launches — please confirm the time against an authoritative source. Mark Utility Labs is not liable for missed meetings, travel, or other losses arising from use of the app.
The app is provided "as is" and "as available", without warranties of any kind, express or implied, including fitness for a particular purpose.
Please don't reverse engineer, resell, or pass the app off as your own. That's the whole list.
If these terms change, we'll update the "Last updated" date above. Continued use after a change means you accept the updated terms.
Questions about these terms? Please contact us at:
Mark Utility Labs
Email: mark@vibecode.review