Comparison

ZoneTime vs Calculator T

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

Head to head
About

ZoneTime

Easily compare timezones to schedule meetings and avoid calling people at inconvenient hours. The app features a widget for quick glances and a table to compare up to 20 locations, automatically adjusting for Daylight Saving Time.

Highlights
  • View overlapping timezone hours
  • Schedule meetings across timezones
  • Today Widget for quick time checks
  • Compare up to 20 locations
  • Color-coded 'OK to call' times
  • Automatic Daylight Saving Time adjustment
  • Create calendar events across timezones
Features
Read full description

ZoneTime offers a quick and easy way to view overlapping timezone hours, and setup meetings. ZoneTime can help you: * stop waking up your friends and family when you call them overseas. * catch your international colleagues while they're still in the office. * compare timezones between a flight's origin and destination. Included Features * ZoneTime Today Widget now allows you to quickly glance at times across your configured locations without needing to open the app, or unlock you phone. * An easy to use table to compare today's times for up to 20 locations at a time. * Choose from cities from around the globe * Color codes times based on whether it's 'OK' to call. * Automatically adjusts for Daylight Saving Time for each Location. * Edit and rearrange locations you want to compare timezones. * Compare timezones in landscape or portrait orientation. * Create an calendar event across multiple timezones

About

Calculator T

This app offers advanced scientific calculation and unit conversion capabilities. It features a history tape, memory functions, and supports complex mathematical operations. It also includes currency exchange rates and a wide range of measurement conversions.

Highlights
  • Standard and scientific function modes
  • Extensive unit conversion (over 300 units)
  • History tape for last 100 records
  • Memory buttons (MS, M+, M-, MR, MC)
  • Copy/paste functionality for equations and results
  • Support for large number calculations and scientific notation
  • Currency exchange rate conversion
Features
Read full description

● Functional Features: 1. Supports standard and scientific function modes. 2. Supports many unit conversion. 3. Displays both the equation & the result. 4. History Tape View - the most recent 100 historical records are automatically saved on your device, you can get them when you open the APP next time. 5. Supports 5 memory buttons and multiple memory records: MS (M Save), M+, M-, MR (M Recall) and MC (Clear Memory), If you often use Windows calculators, then you should be familiar with them. ^_^ 6. Supports copying for both current input and historical records by tap & hold on it - you can copy the equation/expression or the result to the clipboard. 7. Supports pasting equation/expression into input box with robust expression parsing capabilities from the clipboard. 8. Supports long equation/expression input - maximum 1500 characters. 9. Supports insert the equation or result of the historical record into the input box by tap & hold on it. 10. Optimized the layout for iPad, designed with elegant, easy and intuitive interface. 11. Turn on the F-E button to force convert the result to E-notation (scientific notation). 12. When you press the equals button, the APP will automatically fill in any unclosed parentheses in the equation. 13. Supports Equals Repeat function - the APP will automatically repeat it if the last calculation is simple arithmetic operations (+, -, ×, ÷). 14. No ads. ● Math & ALGEBRA Features: 1. Supports 32-bit input precision & calculation precision, this means you can enter 32-bit integer or 32 decimal places. 2. Supports input of maximum scientific notation exponent "9999", eg. 999999E9999. 3. Supports big integer & rational number: For the factorial calculation of positive integer, up to 10000! (about 2.846E+35659). For the calculation result, maximum support 9.999E+99999999. 4. Support constants π, e. 5. Supports switching three angle units (RAD, DEG, GRAD), instead of applying it to the entire equation, we identify the unit of angle for each trigonometric function, so you get a clearer understanding of what the equation means. 6. Supports advanced calculations, including n!, ^, mod, √, log, ln, cube, square, cube root, y root, abs, ceil, random, floor and exponential functions etc. 7. Supports trigonometric functions (sin, cos, tan, asin, acos, atan) and hyperbolic functions (sinh, cosh, tanh, asinh, acosh, atanh). ● Unit Converter Features: 1. Supports multiple weight and measurement unit conversions - Volume, Length, Weight & Mass, Time, Energy, Area, Speed, Temperature, Power, Data, Pressure and Angle. 2. Supports currency exchange rate conversion (over 160 different currency units, and exchange rate data are hourly updated). 3. Supports 300+ Units. 4. Supports favorites function for quick conversions - allows setting 4 frequently used units for each conversion category. 5. We take the accuracy of conversion very seriously, and therefore, We had carefully verified the conversion values of each unit. Such as: when it comes to the electron-volt, many converters use different values, such as 1 eV = 1.60217656535E-19 J, 1 eV = 1.602176473E-19 J, and so on. However, we found that the CODATA 2018 recommended value (latest version) is 1 eV = 1.602176634E-19 J, so we use this latest recommended value. ● Multiple Languages: 1. English 2. Japanese 3. Chinese If you’re using an iPad or iPhone, you can enjoy the Calculator T application, hope it can assist you with your studies and work. If you find it useful, please consider supporting us by leaving a positive review and sharing your suggestions. Thanks :)

Screenshots

ZoneTime4 screens
Calculator T4 screens

Verdict

The call

The clearest difference is update cadence: Calculator T at every 2 days against ZoneTime's every 3 months. ZoneTime's advantage is iOS requirement (8.0 vs 11.0). On price, review sentiment, ads and in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

ZoneTime ships an update every 3 months, Calculator T every 2 days. The most recent releases landed on September 9, 2026 and June 1, 2026 respectively.

Scorecard2 real differences · 8 level
ZoneTime versus Calculator T: the parameters behind the verdict, then further details
ParameterZoneTimeCalculator T
PriceFreeFree
Rating5.0 (1 ratings) — better—
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings1 — better—
Update frequencyEvery 3 monthsEvery 2 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS8.0 — better11.0
Further details — not scored
Size26 MB16 MB
Age rating4+4+
DeveloperGlen TregoningXiao Hou Yi Sheng Traditional Chinese Medicine Technology (Shenzhen) Co., Ltd

Customer experience

ZoneTime

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Calculator T

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

ZoneTime

No in-app purchases

None

Calculator T

No in-app purchases

Questions

Is ZoneTime free?
ZoneTime is free to download, with no in-app purchases.
Is Calculator T free?
Calculator T is free to download, with no in-app purchases.
Do ZoneTime or Calculator T have ads?
Neither ZoneTime nor Calculator T shows ads.
Which is updated more often, ZoneTime or Calculator T?
ZoneTime ships an update every 3 months, and Calculator T every 2 days. Most recently, ZoneTime was updated on September 9, 2026 and Calculator T on June 1, 2026.

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