Comparison

World Clock vs Overlap

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

Head to head
About

World Clock

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
Read full description

"World Clock" is the best app to calculate time differences all over the world. All cities' times change automatically just by scrolling it with your finger. Therefore, you don't need to add or subtract times any more to calculate time differences. ■■Features■■ -Scrolling the time bar on the side of the screen up and down simultaneously changes the time in each city to the future or past. -Double-tap the time bar to change the time unit between 1 minute and 1 hour. -You can add any city from the list of cities provided in the app. -Tap each city to specify the date and time directly. -Press and hold on a city to change the city and edit the custom name. -Only one fixed city can be displayed at the top of the screen. ■■Examples of use■■ -International meeting planner -International call -Trip planning Disclaimer:This application has been built with extreme care and attention. However, it does not guarantee the accuracy of the names and times of the cities displayed. Please note that we are not liable whatsoever for any profit loss, or any other form of loss experienced by the customer from using this application. ※We don't have any time difference data in our app. We have been inquiring about time differences of each city to iOS. Therefore, “World Clock” shows you the time of iOS. As a result, depending on the version of iOS you are using, the exact time may not be displayed. If you find a time lag in our app, please confirm default "Clock" app on your iPhone. If the time in "Clock" app is the same with the time in our “World Clock”, it means that our app is running normally. ※Abbreviated name of time zone was originally researched and added. If you notice any mistakes, please contact us from the support site. ※The screenshots are specially edited not to show ads.

About

Overlap

Easily find optimal meeting times across different time zones with a visual graph. Set custom availability for each location and sync with your calendar to avoid scheduling conflicts. Share convenient times directly from the app.

Highlights
  • Visual Overlap Graph for meeting times
  • Customizable availability hours per time zone
  • Calendar event integration
  • Multiple time zone display
  • Time zone renaming
  • Lock Screen Standby Mode widget
Features
Read full description

Find the perfect time to catchup across multiple time zones without the mind-bending math. Overlap is a smart world clock that helps you connect with people in different time zones. It makes it simple to see the time in multiple places at once, and its fun Overlap Graph is a unique visual way to quickly find convenient meeting times across the world. You can choose ‘available’ hours for each time zone. For example Dan in London might be available from 2pm to 5pm and Rashida in Sydney might be available from 7am to midday. Bring up the Overlap Graph and it will magically show you the most compatible times to schedule your catchup. Overlap also displays your calendar events, so you can always find a time that suits your schedule. Available on iPhone, iPad and Mac. • You can see multiple time zones in one beautiful UI • You can swipe left and right to quickly move through time. • You can customize 'availability' for each timezone - this could mean office hours for a meeting or simply when you're available for a group chat with your far-flung family -no more 'Sorry that's 3am for me!' • You can rename each time zone; for example, you might simply rename a time zone to say 'Grandma' or the name of a client you work with. Or perhaps your Grandma is your client, no judgement here. • You can hide time zones that you don’t need right now so it’s always easy to focus on what you need to know. • You can show your calendar events so you can always choose a time that fits your schedule. • Once you’ve chosen a great time its easy to share it via your favorite messaging app or create a calendar event. • Standby Mode is a Lock Screen feature that activates automatically when your iPhone is charging in landscape mode. The Overlap widget fully supports this mode!

Screenshots

World Clock4 screens
Overlap4 screens

Verdict

The call

The clearest difference is rating: Overlap at 4.8 against World Clock's 3.9. Overlap also leads on in-app purchases (none vs 1) and ads (none vs shown). World Clock's advantage is review sentiment (77% vs 67%) and update cadence (every 6 weeks vs every 3 months). On price and iOS requirement 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 Clock sells 1 one-off in-app purchase. Overlap asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Overlap holds the better App Store score, 4.8 against 3.9. That said, the two scores are not equally well evidenced: Overlap has 849 ratings behind it against 14, so its average is the more settled of the two. Written reviews complicate that: 77% of World Clock's written reviews are positive against 67% of Overlap's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

World Clock ships an update every 6 weeks, Overlap every 3 months. The most recent releases landed on June 9, 2026 and September 24, 2026 respectively.

Scorecard8 real differences · 2 level
World Clock versus Overlap: the parameters behind the verdict, then further details
ParameterWorld ClockOverlap
PriceFreeFree
Rating3.9 (14 ratings)4.8 (849 ratings) — better
Positive reviews77.4% of reviews — better67.2% of reviews
Number of ratings14849 — better
Update frequencyEvery 6 weeks — betterEvery 3 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationAd-supportedFree — better
DevicesiPhone, iPodiPhone, iPad, iPod, Mac — better
Requires iOS15.615.0 — better
Further details — not scored
Size6 MB71 MB
Age rating4+4+
DeveloperYuki FukuiBonobo

Customer experience

World Clock

All ratings13 ratings
Positive76.9%
Neutral0.0%
Negative23.1%
Written reviews62 reviews
Positive77.4%
Neutral6.5%
Negative16.1%

Overlap

All ratings849 ratings
Positive95.5%
Neutral2.4%
Negative2.1%
Written reviews247 reviews
Positive67.2%
Neutral11.3%
Negative21.5%

Bugs and requests

World Clock

Not enough reviews yet to summarise bugs or requests.

Overlap

Reported bugs

4 issues
  • Timezone data not updating correctly
  • Inability to delete unwanted timezones
  • Inconsistent behavior across platforms
  • Typing issues on Mac version

Requested features

5 requests
  • Add option to reorder timezones
  • Implement 24-hour clock display
  • Allow customization of colors and backgrounds
  • Integrate with calendar for scheduling
  • Add weather information for each timezone

In-app purchases

1 purchases

World Clock

One-time1
  • Remove Advertisement$1.99
None

Overlap

No in-app purchases

Questions

Is World Clock free?
World Clock is free to download, with in-app purchases available.
Is Overlap free?
Overlap is free to download, with no in-app purchases.
Which has better reviews, World Clock or Overlap?
Overlap is rated higher. World Clock averages 3.9 out of 5 from 14 ratings, while Overlap averages 4.8 from 849 ratings.
Do World Clock or Overlap have ads?
World Clock shows ads; Overlap does not.
Which is updated more often, World Clock or Overlap?
World Clock ships an update every 6 weeks, and Overlap every 3 months. Most recently, World Clock was updated on June 9, 2026 and Overlap on September 24, 2026.

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