Comparison

Onetime. vs World Time Clock Master

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Onetime.

Visualize multiple world time zones on a single, intuitive dial. This app simplifies international scheduling and communication by displaying cities as they move through day and night, automatically handling daylight saving changes. Effortlessly find the perfect time for calls or to connect with loved ones globally.

Highlights
  • Single, easy-to-read time zone dial
  • Visualizes cities moving through day and night
  • Automatic daylight saving time adjustments
  • Timetravel™ feature for scheduling
  • Shareable time invites
Features
Read full description

One world. Onetime. Finally, a world clock that integrates all time zones into one easy-to-read dial. We are all living and working globally more and more, so we needed a way to simply see the time in cities around the world at a glance. That’s how Onetime was born. Built on the metaphor of the earth’s rotation, Onetime displays all the cities that matter to you as they move through the day and night in a natural, clockwise direction referencing the international date line. Whether you are scheduling an international call or checking to see what time it is back home, Onetime is the clock for you. No more mistakes adding and subtracting hours, no more confusing GMT numbers, no more remembering daylight savings calendars. Onetime takes care of it all, automatically. And with Timetravel™, you can fly through time so that you quickly find the right moment to schedule that important teleconference with your international colleagues or catch your loved ones before their bedtimes. The „Share“ feature lets you choose a date with TimeTravel and send an invite via message or email. Give up your wall of newsroom clocks and switch to Onetime today. Onetime. By FLUID. ABOUT FLUID Onetime was created by the award-winning design firm FLUID. With our locations in Munich and Silicon Valley and our international client base, the FLUID team is a heavy Onetime user, too.

About

World Time Clock Master

Effortlessly manage multiple time zones with this app. Convert times instantly, schedule events, and view global clocks at a glance with interactive widgets. Features atomic accuracy and a vast database of locations.

Highlights
  • Multiple time zone display
  • Interactive time conversion
  • Event scheduling
  • Atomic time accuracy
  • Dynamic home screen widgets
  • List mode for text view
  • Real moon phases and sunrise/sunset
Features
Read full description

THE EASIEST WAY TO DEAL WITH MULTIPLE TIMEZONES + INTERACTIVE WIDGETS Sick of screwing up meeting times and missing calls? This app cuts through time-zone confusion and hands you the perfect hour at a glance. Forget guesswork — just click, connect, and impress. KEY FEATURES EVENT SCHEDULING MADE EASY Found the perfect meeting time? Add events to your calendar with just a tap, and never miss an international webinar, call, or special moment again. ATOMIC ACCURACY No drift, no guesswork. Each second syncs with the atomic standard, so you can trust every moment. Extensive Time Zone Database: Tap into over 160,000 locations and time zones including GMT, UTC, and more. UNIFIED CLOCK FACE View all your essential time zones at a glance on one beautifully designed, customizable clock face. Whether you prefer digital or analog displays (or even military time), everything is exactly where you need it. INTERACTIVE TIME CONVERSION Convert times instantly by simply twisting or swiping across the clock face. Watch as your selected time zones update in real time—making planning international calls, meetings, or travel effortless. DYNAMIC WIDGETS Access global times without even opening the app. Our interactive home screen widget lets you drag a simple line to reveal and convert times, ensuring you’re always in sync no matter where you are. LIST MODE Get a clean, text-based view of all your cities in one column. See times and dates at a glance, and scroll to check future or past hours. It’s a no-fuss way to track the world’s clocks. FEELS LIKE A LUXURY TIMEPIECE We poured effort into details most people never notice — and we’re okay with that. Our users aren’t “most people.” Details include: — Real Moon Phases — Real Moon Rotation — Real Sunrise & Sunset — Advanced City Lights — Haptic Feedback * * * World Clock Master offers a premium subscription: Subscribe to get access to unlimited timezones, interactive widgets, customizations, and timely automatic updates of our timezone database of more than 160,000 locations and timezones. – Length of subscription: 1 month or 1 year – Payment will be charged to iTunes Account at confirmation of purchase – Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period – Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal – Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase – Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable – Terms & Conditions: https://timemaster.s3.amazonaws.com/Time-master-terms.pdf

Screenshots

Onetime.4 screens
World Time Clock Master4 screens

Verdict

The call

The clearest difference is rating: World Time Clock Master at 4.6 against Onetime.'s 3.5. World Time Clock Master also leads on update cadence (fortnightly vs every 11 months) and ratings volume (816 vs 39). Onetime.'s advantage is in-app purchases (none vs 13) and iOS requirement (13.0 vs 17.0). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. World Time Clock Master sells 10 in-app purchases, starting at $2.99 per month. Onetime. asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

World Time Clock Master holds the better App Store score, 4.6 against 3.5. That said, the two scores are not equally well evidenced: World Time Clock Master has 816 ratings behind it against 39, so its average is the more settled of the two. Written reviews point the same way: 51% of Onetime.'s written reviews are positive against 66% of World Time Clock Master's.

UpkeepUpdate frequency

Onetime. ships an update every 11 months, World Time Clock Master fortnightly. The most recent releases landed on September 17, 2026 and September 20, 2026 respectively.

Scorecard7 real differences · 3 level
Onetime. versus World Time Clock Master: the parameters behind the verdict, then further details
ParameterOnetime.World Time Clock Master
PriceFreeFree
Rating3.5 (39 ratings)4.6 (816 ratings) — better
Positive reviews51.5% of reviews65.8% of reviews — better
Number of ratings39816 — better
Update frequencyEvery 11 monthsFortnightly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterSubscription
DevicesiPhone, iPodiPhone, iPad, Vision Pro — better
Requires iOS13.0 — better17.0
Further details — not scored
Size2 MB236 MB
Age rating4+4+
DeveloperFLUID Design GmbHAlex Komarov Inc.

Customer experience

Onetime.

All ratings39 ratings
Positive59.0%
Neutral2.6%
Negative38.5%
Written reviews134 reviews
Positive51.5%
Neutral5.2%
Negative43.3%

World Time Clock Master

All ratings816 ratings
Positive90.8%
Neutral2.8%
Negative6.4%
Written reviews76 reviews
Positive65.8%
Neutral5.3%
Negative28.9%

User reviews

Onetime.

From 39 App Store ratings

What we love

  • ✨ Beautiful and elegant design
  • 👍 Intuitive and easy to use interface
  • 🌍 Great for visualizing time differences
  • 💡 Unique and innovative visualization
  • ✅ Works well for scheduling

Room to improve

  • 🐛 Data quality issues (incorrect times)
  • 🐛 Inability to add cities
  • 🐛 App crashes or freezes
  • 🐛 City search not working
  • 🐛 Some cities not recognized

World Time Clock Master

From 816 App Store ratings

What we love

  • 🚀 Delightful scheduling assistance
  • 👍 Feature improvement
  • 👍 The best Timezone helper
  • 👍 One of the best clocks around
  • 👍 The Widget is so damn cool!

Room to improve

  • 🐛 Problemas al actualizar
  • 🐛 Sticky signup interface
  • 🐛 Demo not enough
  • 🔒 NOT A FREE APP
  • 💰 Terrible monetisation model compared to previous app

Bugs and requests

Onetime.

Reported bugs

8 issues
  • Incorrect time zone data for some cities (e.g., Taipei, São Paulo)
  • App freezes when trying to add cities
  • City search function not working ('No cities found')
  • App crashes on launch after updates
  • Time travel feature stops working with certain cities
Show 3 more
  • Scrolling back and forth in time no longer possible
  • App not working with latest iOS versions
  • Default 'My Time' zone cannot be removed

Requested features

9 requests
  • Ability to add descriptive labels for cities
  • Ability to add GMT/UTC time
  • Ability to add time zones manually
  • Homescreen widgets
  • Ability to toggle cities instead of removing
Show 4 more
  • iPad version
  • Tutorial on first launch
  • Option to reverse view horizontally
  • Ability to search future dates

World Time Clock Master

Reported bugs

4 issues
  • Lose all the registered locations after updating the app
  • Sticky signup interface
  • Widget doesn't work
  • GMT and London currently have a 1 hour time difference between the two locations, but the app shows them the same time

Requested features

4 requests
  • Add the time difference in hours between the default location and other locations in both the widget and the app
  • See my calendar events on the dial
  • Make a paid tier that doesn't collect my data
  • Add new event to a Calendar

In-app purchases

None

Onetime.

No in-app purchases

10 purchases

World Time Clock Master

Subscriptions6
  • 1 month3 variants$2.991 Month
  • 3 months$3.993 Months
  • 1 year1 Year trial2 variants$11.991 Year
Show 3 more
  • 1 year3 Days trial$11.991 Year
  • 1 year$11.991 Year
  • 1 year3 Days trial$19.991 Year
One-time4
  • Lifetime$29.99
  • Lifetime$49.99
  • Lifetime$79.99
Show 1 more
  • Lifetime$99.99

Questions

Is Onetime. free?
Onetime. is free to download, with no in-app purchases.
Is World Time Clock Master free?
World Time Clock Master is free to download, with in-app purchases available.
Which has better reviews, Onetime. or World Time Clock Master?
World Time Clock Master is rated higher. Onetime. averages 3.5 out of 5 from 39 ratings, while World Time Clock Master averages 4.6 from 816 ratings.
Do Onetime. or World Time Clock Master have ads?
Neither Onetime. nor World Time Clock Master shows ads.
Which is updated more often, Onetime. or World Time Clock Master?
Onetime. ships an update every 11 months, and World Time Clock Master fortnightly. Most recently, Onetime. was updated on September 17, 2026 and World Time Clock Master on September 20, 2026.

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