Twixt Time helps track the longterm accuracy of watches and clocks, by collecting & analyzing precisely timed snapshots of their dials.
Use Twixt Time to take a picture of the dial of an analog clock or watch. Each picture captures the exact time displayed on the dial. Twixt also notes the precise instant that the each snapshot was taken, by communicating with highly accurate NTP timeservers on the Internet.
A new snapshot of each timepiece can be added everyday. Using the information from 2 or more snapshots of the same timepiece, Twixt will calculate and show you how precisely the watch or clock is keeping time.
Twixt tracks the most recent rate, overall average rate, and cumulative gain or loss for each timepiece.
Supported dial configurations:
* Hour & minute hands with a central seconds hand
* Hour & minute hands with seconds displayed in a subdial
* Hour & minute hands only
Does Twixt Time work with GMT watches?
Yes. Twixt Time does not need to track the 24 hour hand of GMT watches to measure their precision. It is only necessary to track the hour, minute, and second hands. For GMT watches with central seconds, select the "central seconds" layout. For GMT watches with an offset or subdial seconds hand, select the "subdial seconds" layout. Twixt Time automatically monitors timezone changes based on the timezone setting of the iPhone or iPod touch.
Does Twixt Time work with chronograph watches?
Yes. The chronograph functions of a watch do not need to be measured to track the precision of the watch. Twixt Time tracks the precision of chronographs, as well as watches with other complications, in the exact same way that it tracks the precision of a normal, time-only watch. If the central seconds hand can be stopped and reset with the chronograph function, select the "subdial seconds" layout to track the small seconds hand with Twixt Time. If the central seconds hand continues to move when the chronograph is stopped, but the small seconds hand stops, select the "central seconds" layout to track the central seconds hand with Twixt Time. Most chronographs will use a subdial seconds layout.
Does Twixt Time work with watches that have an offset seconds hand?
Yes. For watches with a second hand that is not concentric with the hour and minute hands, select the "subdial seconds" layout.
Does Twixt Time work with quartz watches and clocks? Or other watches and clocks that are powered by batteries?
Yes. Twixt Time works with battery powered watches and clocks that display the time with an hour, minute, and/or second hand. It does not work with watches or clocks that only display the time digitally.
Twixt Time is not affiliated with or endorsed by any watch or clock brand. The timepieces shown are for demonstration purposes only.
This update addresses a minor caching issue.
Ratings and Reviews
Always says 12+ hrs even if it’s only a few seconds
The app was working well but now it always displays as the time advanced as 12+hrs when it may have only been a few seconds. Sad to see
Pretty good, but only if you picture is.....
On the average, the app works pretty well. I am tracking 4 different timepieces, all with automatic movements. Once you have a few entries for that timepiece, it averages out to right at what I was calculating by hand, using an atomic clock.
The most difficult part is in taking a quality image of the face. You need even lighting, with no glare (like from a lightbulb), and you need to hold the phone "square" to the watch face. You need to be able to see every minute market, regardless of how many you have, with equal clarity and they must all be at the same angle. If you do not accomplish this, the "12:00 marker" will not line up properly and you will notice that the lines for the hands do not fall perfectly in the middle of each hand. If these do not happen, you will receive inaccurate measurements. Should you proceed, despite the problems I described, it will require several measurements before the average works out to be accurate.
Used to be perfect, now it crashes constantly.
This app used to be amazing, however now it crashes every time you try to take a picture. Very disappointed! Get Tooltime instead. Developer seem unwilling to fix it.
Update September 23,2017:
App now crashes every time you try to resize a picture. You take the pic, app blows it way out of proportion (to the point it's nearly unusable), you zoom out to try and navigate m, and the damned thing crashes STILL!
Developer is cruel and uncaring, refuses to fix.
Developer Response ,
If you are continuing to encounter crashes, please get in touch at firstname.lastname@example.org so we can get to the bottom of this for you.
With Family Sharing set up, up to six family members can use this app.