Comparison

Emerald Chronometer vs DayCalc Pro

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

Head to head
About

Emerald Chronometer

Experience highly detailed mechanical watch faces with advanced astronomical and clock complications. Track celestial events, manage time with precision, and explore historical and future dates with interactive displays. Optimized for iPhone and iPod touch.

Highlights
  • Accurate astronomical data (4000 BCE - 2800 CE)
  • Sun, Moon, and planet rise/set times
  • Mechanical display of Moon phases
  • Precise local and UTC time
  • Chronograph with split timer
  • World-time and calendar watches
  • Interactive time-travel simulation
Read full description

These models of high-end mechanical watch faces contain many of the most complex "complications" found in real watches, plus refinements found nowhere else. All displays maintain the look and feel of real mechanical objects, but with the time and location accuracy of the iPhone. NOTE: This app (Emerald Chronometer) is optimized for the iPhone and iPod touch. Please also see Emerald Chronometer HD, a separate product optimized for the iPad. Astronomy features: - Highly accurate data from 4000 BCE to 2800 CE - Times of rise and set for the Sun, the Moon, and the 5 classical planets - The correct shape and orientation of the Moon in all phases but still using a mechanical display - Relative positions of the Sun, Moon, 6 planets and the constellations of the zodiac - "Compass functions" show the elevation and azimuth of the Sun, the Moon, and the 5 planets - The Equation of Time, solar time and sidereal time - Eclipse predictor (lunar node indicators and separation indicator) - User settable geographic location and timezone using an 80,000 city database - A unique face showing the rise and set times of all 5 classical planets plus the Sun and the Moon at once Clock features: - Day/date/month/year indicators, using mechanical wheels - Local and UTC time - Chronograph (stopwatch) with split timer, 1/10 sec accuracy - Alarm clock and interval timer; notifications are delivered in iOS 4 if the app is not running** - World-time watch with 24-city ring on one side and 4 subdials on the other - Calendar watch with rotating wheels showing a full month at a time - Most watches with 1/5 sec or 1/10 sec precision - Synchronized with standard atomic clocks via NTP There are 16 watches in all, with 27 total watch faces (including front and back sides). A setting is available to allow the display to stay on only when plugged in. Play with the watches by tapping on the crown and moving the hands, or press and hold on a date window to zoom through time to see the effect on the heavens. Then just use them to show you when it's time for a break. A complete description of each application feature can be found in the built-in Help screens and on the Emerald Sequoia LLC Web Site, which also includes a demo movie. A developer's blog may also be found at http://emeraldsequoia.com/esblog/ . If you are having any trouble with the application whatsoever, please see our FAQ on the support page listed below and then contact us through that page if your problem is not resolved. We take pride in responding promptly to all support email requests. **NTP accuracy is not guaranteed for alarm delivery if the app is not running. (NTP requires Internet access. Like all apps Emerald Chronometer can not change the device's internal clock.)

About

DayCalc Pro

This app combines a powerful calculator with a comprehensive unit converter. It offers standard and scientific calculations, allows notes to be added to history, and supports a wide range of units and custom conversions. Enjoy a user-friendly interface with customizable themes and watchOS integration.

Highlights
  • Standard and scientific calculator
  • Add notes to calculations
  • Over 600 units in 20 categories
  • Custom unit creation
  • Automatic currency exchange rate updates
  • Dark Mode support
  • Apple Watch integration
Features
Read full description

DayCalc is an easy to use, beautifully packaged calculator and Unit Converter, includes standard, scientific and fractions calculator, best calculator for your iPad, iPhone and Apple Watch! Calculator: - Live voice calculator - Add notes to history of your calculations, and you can share - Choose between a basic calculator or scientific calculator with more than 30 scientific operations - Use both calculators in portrait or landscape mode (both iPhone and iPad), and split screen support for iPad - Auto adjust height of the history list, no matter how long the calculation process can be displayed in full - Allows locking of calculation history, cannot be deleted and modified after locking - Full watchOS 4 and later support - Support iOS 9 and later spotlight search - Support Dark Mode Unit Converter: - Over 600+ units in 20 categories. - Allows you to add your own unit data, make your own unit converter that meets all your requirements. - Support more than 150 kinds of currency, conversion exchange rate automatic updates - The simplest way to create and use favorite lists. - Add the constant value of your frequently used, it can easily and quickly reused. - Flexible search feature that lets you quickly find what you want the unit and automatically saves your search history. Basic functions: - 50+ beautiful themes for you to choose - View and edit a history of your calculations on the History Panel - Multiple Button sounds, and button sound is mutable URL schemes: HCDayCalcPro:// Download it now and feel of this calculator is how classic

Screenshots

Emerald Chronometer4 screens
DayCalc Pro4 screens

Verdict

The call

The clearest difference is price: Emerald Chronometer at Free against DayCalc Pro's $0.99. Emerald Chronometer also leads on in-app purchases (none vs 9) and rating (4.9 vs 4.6). DayCalc Pro's advantage is update cadence (every 6 weeks vs every 22 months) and iOS requirement (13.0 vs 15.0). On ratings volume 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

Emerald Chronometer is free to download; DayCalc Pro costs $0.99 up front. DayCalc Pro sells 9 one-off in-app purchases. Emerald Chronometer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Emerald Chronometer holds the better App Store score, 4.9 against 4.6. Both are backed by a comparable volume of ratings — 105 and 177 respectively. Written reviews point the same way: 97% of Emerald Chronometer's written reviews are positive against 86% of DayCalc Pro's.

UpkeepUpdate frequency

Emerald Chronometer ships an update every 22 months, DayCalc Pro every 6 weeks. The most recent releases landed on September 18, 2026 and September 16, 2026 respectively.

Scorecard7 real differences · 3 level
Emerald Chronometer versus DayCalc Pro: the parameters behind the verdict, then further details
ParameterEmerald ChronometerDayCalc Pro
PriceFree — better$0.99
Rating4.9 (105 ratings) — better4.6 (177 ratings)
Positive reviews96.8% of reviews — better85.5% of reviews
Number of ratings105177 — better
Update frequencyEvery 22 monthsEvery 6 weeks — better
Ads—No
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Apple Watch — better
Requires iOS15.013.0 — better
Further details — not scored
Size311 MB99 MB
Age rating4+4+
DeveloperScapa Flow, LLC良峰 侯

Customer experience

Emerald Chronometer

All ratings96 ratings
Positive97.9%
Neutral1.0%
Negative1.0%
Written reviews63 reviews
Positive96.8%
Neutral3.2%
Negative0.0%

DayCalc Pro

All ratings177 ratings
Positive92.7%
Neutral2.8%
Negative4.5%
Written reviews173 reviews
Positive85.5%
Neutral5.2%
Negative9.2%

Bugs and requests

Emerald Chronometer

Not enough reviews yet to summarise bugs or requests.

DayCalc Pro

Reported bugs

10 issues
  • Latest update stuck on download/installation loop
  • Display rendering issues in landscape mode on iPhone 12/13 mini
  • Fraction results display truncated with large numbers
  • Fraction operator placement incorrect during multi-step calculations
  • Currency conversion broken after favoriting currencies
Show 5 more
  • Copy expression only copies first number
  • Exponent calculation: .35 / 1 EE 6 returns 350,000 instead of correct value
  • Fahrenheit to Celsius conversion inaccurate (8°F returns 1.3°C)
  • App becomes unusable after using unit conversion feature
  • iOS 6 compatibility: black display and crashes

Requested features

5 requests
  • Cursor movement for easier digit and symbol editing
  • Back button to delete individual numbers instead of clearing all
  • History display directly above input without clicking
  • Back button in converter functions for easier navigation
  • Improved animated transitions for better aesthetics

In-app purchases

None

Emerald Chronometer

No in-app purchases

9 purchases

DayCalc Pro

One-time9
  • Constants Pack$0.99
  • Festivals Theme Pack 1$0.99
  • Season Theme Pack 1$0.99
Show 6 more
  • Bird Theme Pack 1$0.99
  • Insects Theme Pack 1$0.99
  • Season Theme Pack 2$0.99
  • Festivals Theme Pack 2$0.99
  • Custom Unit Pack$1.99
  • Complete Pack$4.99

Questions

Is Emerald Chronometer free?
Emerald Chronometer is free to download, with no in-app purchases.
Is DayCalc Pro free?
DayCalc Pro costs $0.99, and also offers in-app purchases.
Which has better reviews, Emerald Chronometer or DayCalc Pro?
Emerald Chronometer is rated higher. Emerald Chronometer averages 4.9 out of 5 from 105 ratings, while DayCalc Pro averages 4.6 from 177 ratings.
Which is updated more often, Emerald Chronometer or DayCalc Pro?
Emerald Chronometer ships an update every 22 months, and DayCalc Pro every 6 weeks. Most recently, Emerald Chronometer was updated on September 18, 2026 and DayCalc Pro on September 16, 2026.

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