Atomic Clock PRO vs Chronometer

Get accurate time on your iPhone and iPad by syncing with an official atomic clock time server. Download now for free! If you want exact time, a precise time reference, or an easy-to-read clock display, this app is designed for that. It automatically recognizes your time zone, lets you use one of your own photos as the background, and lets you switch between a digital display and a classic analog clock with a simple swipe. It is ideal as a personalized desk clock, a reliable travel companion, an everyday reference clock, or when you need exact time to set a mechanical watch accurately. Overview: - Accurate and precise time synced from an official atomic clock time server - Automatically recognizes your time zone and shows the current local time - Choose digital, analog, or combined analog and digital clock displays - Swipe to switch between clock displays - Resize the digital clock for a larger or smaller display - Includes time (hours, minutes, and seconds), date, and day of the week (optional) - Optional sound every second or every minute - Change clock and background colors - Use your own photos as background images - Choose atomic clock sync or your device's system clock - Option to keep the screen awake while the app is open - Works in portrait and landscape mode - For iPhone and iPad Helpful for: - A personalized desk clock at home or at work - Getting the correct local time while traveling - Setting a mechanical watch accurately - A clear reference clock when you want accurate, easy-to-read time PLEASE NOTE: You can switch between the analog and digital clock by swiping left or right across the clock. Disclaimer: Please note that whilst all reasonable care has been taken to make this application as accurate as possible we can not guarantee 100% accuracy. Standard Apple Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Chronometer – Mechanical Watch Accuracy This app helps you track the real-world accuracy and long-term rate performance of your mechanical watch. It provides an easy way to measure the daily rate of your watch against an accurate NTP time reference and to follow its performance over days, weeks or months. Before starting a new measurement series, synchronize your watch with an accurate time reference. Do not reset the watch during the measurement period. An internet connection is required to obtain the precise NTP reference time. How to measure your watch 1. Start the app and wait until the NTP server has synchronized. The NTP time turns green when the reference time is available. 2. Point the camera at the watch dial. You can use pinch-to-zoom and, on supported devices, the macro capability for precise reading of the seconds hand. 3. Tap the camera button to freeze the image. The app records the corresponding NTP reference time. 4. Read the exact time from the frozen image and adjust the displayed watch time using the picker wheels. 5. If desired, enter the current altitude above sea level. 6. Tap Save Rate to store the measurement. 7. Tap the camera button again to return to the live camera view. For the best results, measure your watch once per day at approximately the same time. If more than one day passes between two measurements, the app automatically calculates the average daily rate for that interval. Performance evaluation The graph shows the daily rate of your watch together with the standard COSC limits and the more demanding COSC Excellence limits. After at least 15 measurements, the app provides an additional COSC Evaluation based on the most recent 15 daily rate values. The evaluation includes a COSC pass/fail assessment and a Concours Score from 0 to 500 points, derived from the chronometer competition formula. The Concours Score does not include the thermal coefficient (CT). Temperature testing, controlled positional changes, magnetic exposure and shock testing cannot be reproduced during normal everyday use. The result is therefore not an official COSC certification, but a practical evaluation of the real-world rate performance of your watch. The complete measurement history can be exported as a CSV file for further analysis. The exported data includes the date, absolute rate difference, daily rate difference and altitude above sea level. Time reference: Swiss NTP server ntp11.metas.ch The app also includes a COSC NTP 4 Hz reference dial for calibration and verification of optical timing instruments. Requires iOS 18.6 or later.