# World Clock vs Onetime.

The clearest difference is in-app purchases: Onetime. at none against World Clock's 1. Onetime. also leads on ads (none vs shown) and iOS requirement (13.0 vs 15.6). World Clock's advantage is rating (3.9 vs 3.5) and update cadence (every 6 weeks vs every 11 months). On price, ratings volume and device support there is nothing between them.

Both are free to download. World Clock sells 1 one-off in-app purchase. Onetime. asks for nothing beyond the download.

World Clock holds the better App Store score, 3.9 against 3.5. Both are backed by a comparable volume of ratings — 14 and 39 respectively. Written reviews point the same way: 77% of World Clock's written reviews are positive against 51% of Onetime.'s.

World Clock ships an update every 6 weeks, Onetime. every 11 months. The most recent releases landed on June 9, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | World Clock | Onetime. |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (14 ratings)](https://appshunter.io/ios/app/world-clock-time-converter/id622366157/reviews)** | [3.5 (39 ratings)](https://appshunter.io/ios/app/onetime/id921569664/reviews) |
| Number of ratings | 14 | **39** |
| Positive reviews | **77.4% of reviews** | 51.5% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 6 weeks** | Every 11 months |
| Monetization | Ad-supported | **Free** |
| Size | 6 MB | 2 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yuki Fukui](https://appshunter.io/developer/575924491) | [FLUID Design GmbH](https://appshunter.io/developer/921569663) |

## What reviewers say

### World Clock

[App page](https://appshunter.io/ios/app/world-clock-time-converter/id622366157)

Easily calculate time differences worldwide by scrolling a dynamic time bar. Add any city, set specific dates and times, and plan international meetings or calls effortlessly. The app syncs with iOS time data.

**Highlights:** Dynamic time bar for instant difference calculation, Add and manage multiple cities, Direct date and time specification, Customizable city names, Syncs with iOS time data

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Advertisement | $1.99 | one-time |


### Onetime.

[App page](https://appshunter.io/ios/app/onetime/id921569664)

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:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

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

**What reviewers complain about**

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

**Reported bugs**

- 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

**Requested features**

- 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


## Frequently asked questions

### Is World Clock free?

World Clock is free to download, with in-app purchases available.

### Is Onetime. free?

Onetime. is free to download, with no in-app purchases.

### Which has better reviews, World Clock or Onetime.?

World Clock is rated higher. World Clock averages 3.9 out of 5 from 14 ratings, while Onetime. averages 3.5 from 39 ratings.

### Do World Clock or Onetime. have ads?

World Clock shows ads; Onetime. does not.

### Which is updated more often, World Clock or Onetime.?

World Clock ships an update every 6 weeks, and Onetime. every 11 months. Most recently, World Clock was updated on June 9, 2026 and Onetime. on September 17, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*