TrueOffset

Name: TrueOffset
Rating: 4.9 (8 reviews)
Author: Richard Bollar

Precision NTP Clock

Free · Designed for iPad. Not verified for macOS.

8 Ratings
Age Rating

4+
Years
Category

Utilities
Developer

Richard Bollar
Language

EN
English
Size

4.3
MB

New in 1.4: the radio codes "atomic" clocks listen to, from WWVB to DCF77, spelled out second by second. And TrueOffset is now on the Mac. TrueOffset measures how far your iPhone or iPad's clock is from the world's time servers, and which way. Compare Network Time Protocol (NTP) servers with one another, see how far apart they are, and set any of them as your reference. FIVE CLOCK FACES - 12-Hour Classic — Traditional analog display - 24-Hour Scientific — Full day on one dial - NTP Offset — Dual second hands show device vs. true time - Digital — Large display with millisecond precision - Time Code — A radio time code spelled out second by second UTC & TAI TIME SCALES Show Coordinated Universal Time (UTC) and International Atomic Time (TAI), 37 seconds ahead of it, beside your local time, with deadbeat second hands that step on each second. TIME SIGNALS Hear the true second. Optional pips are timed against your NTP reference, so the start of each one marks the real second, not your device's idea of it. Choose from the classic broadcast signals, synthesized to their published pitch and timing: Six Pips (Greenwich Time Signal), WWV, WWVH, CHU, Jihō, Moscow Six Pips, and Australia's VNG. Sound them on the hour, every 15 minutes, or every minute. Bluetooth or AirPlay speaker running late? Measure its delay with the microphone and TrueOffset compensates. RADIO TIME CODES A clock sold as "atomic" is a radio listening to a distant station that spells out the time one second at a time. TrueOffset plays the codes of WWVB, DCF77, MSF, JJY (40 and 60 kHz), and BPC and shows each second being decoded as it is sent. Try setting a radio-controlled watch with it (beta), or switch on the DCF77 weather seconds to hear how Germany's station once sent a forecast. TRUEOFFSET MASTER CLOCK Our tribute to the U.S. Naval Observatory's telephone time service. A tick sounds every second while a voice announces your local time and then Universal Time, each ahead of a beep that lands on the true second. Prefer it quiet? Switch the voice off and keep the ticks. TrueOffset is not affiliated with the U.S. Naval Observatory. DUAL-STACK COMPARISON Ask one server over IPv4 and IPv6 side by side, to catch two different machines behind one name or a network that answers for both. FLEXIBLE TIME SOURCES Compare against Apple, Google, Cloudflare, NIST, US Naval Observatory, global NTP pools, or add your own servers. The default reference, ntp.trueoffset.app, is a Safran SecureSync 1200 with its own rubidium atomic clock. Set any source as your reference. QUALITY ANALYTICS Eight chart pages show the character of your time sources: - Overview — Every server at a glance - Offset History — Track drift over time - Offset Histogram — How the offsets are spread - Offset Range — Compare consistency across servers - Round Trip and Offset — See whether network delay moves the offset - Clock Sources — Decode reference clocks (GPS, PPS, Rubidium, Cesium) - IPv4 and IPv6 — Compare one server's two addresses - Rankings — Servers scored by jitter and round-trip time, with the steadiest named HELP IN THE APP What an offset is, why your clock drifts, what UTC and atomic time are, and what each screen shows, explained in the app. For anyone who cares how accurate their time really is, and wants to see the difference, not just trust it. Also on Apple TV. FOR TIMEKEEPERS: TRUEOFFSET FOR MAC Run your own time servers? The Mac app, free in this same listing, reads what they record about themselves and charts it, from six hours to a year: - NTPsec, ntpd, chrony, linuxptp, gpsd, Safran SecureSync, and Timebeat - Logs from a folder, or collected over SSH every hour, read-only - Offset, frequency, Allan deviation, temperature, peers, PTP, GNSS sky plots, and each machine's real-time clocks - Restarts, steps, and holdover found and marked, not averaged in - Your servers compared side by side as a fleet More at trueoffset.app/timekeepers --- In appreciation of Emerald Sequoia's Emerald Time.

Ratings & Reviews

4.9

out of 5

8 Ratings

Excellent App!
3d ago
Scott1155
I always used Emerald Time, but the developer stopped developing the app and removed it quite some time ago. About every 6 months I would check the app store in the hopes of finding a similar app. I was so happy when I found TrueOffset today. This app is very similar and works excellent, just what I was looking for. Thank you for bringing back this type of app. My thanks to the developer for an excellent app that performs well and is easy to use. Job well done!
Excellent App!
3d ago
Scott1155

I always used Emerald Time, but the developer stopped developing the app and removed it quite some time ago. About every 6 months I would check the app store in the hopes of finding a similar app. I was so happy when I found TrueOffset today. This app is very similar and works excellent, just what I was looking for. Thank you for bringing back this type of app. My thanks to the developer for an excellent app that performs well and is easy to use. Job well done!
Emerald Time successor?
Apr 7
esambo
Finally an app that comes close what Emerald Time did. I love the millisecond precision and all the insights, and allowing me to add additional servers. Nice UI too.The dual stack comparison doesn’t seem to work for me. It might also be interesting to have two (or more?) different categories of servers, smearing vs non-smearing, as it doesn’t make sense to have some of each, and depending on the use case, one might make more sense than the other.I would also love a feature (on the Clock page) that just selects the best server from my list, just like Emerald Time did, so that I can determine what the most accurate device offset is. I assume the “Device Clock Offset” is based on the currently selected server. It would be nice if I could switch that to the one with the best quality (and perhaps even see which server that was).I also wouldn’t mind paying a few dollars for additional features like that, as long as it’s reasonable and not a subscription.I also wonder if reading the exact millisecond offset on the Clock could be improved with a little dot going around the outside of the analog clock circling, with markers for every 2-10 millisecond, depending on the screen size.Thanks so much
Emerald Time successor?
Apr 7
esambo

Finally an app that comes close what Emerald Time did. I love the millisecond precision and all the insights, and allowing me to add additional servers. Nice UI too.The dual stack comparison doesn’t seem to work for me. It might also be interesting to have two (or more?) different categories of servers, smearing vs non-smearing, as it doesn’t make sense to have some of each, and depending on the use case, one might make more sense than the other.I would also love a feature (on the Clock page) that just selects the best server from my list, just like Emerald Time did, so that I can determine what the most accurate device offset is. I assume the “Device Clock Offset” is based on the currently selected server. It would be nice if I could switch that to the one with the best quality (and perhaps even see which server that was).I also wouldn’t mind paying a few dollars for additional features like that, as long as it’s reasonable and not a subscription.I also wonder if reading the exact millisecond offset on the Clock could be improved with a little dot going around the outside of the analog clock circling, with markers for every 2-10 millisecond, depending on the screen size.Thanks so much
NTP is dead! Long live NTP!
6d ago
K. M. Peterson
I was one of those really saddened by the demise of Emerald Time, and I’m greatly appreciative of the developer for taking up the mantle. There is a lot of information here, and lots to figure out. The only thing I could possibly ask for: sound effects. Having multiple iOS devices with ~ms synchronization emitting a 1- or 5-second tone was a great tool for understanding how location differences could be “heard”. Again, my thanks! UPDATE: thanks for the ticking, and the voice!
NTP is dead! Long live NTP!
6d ago
K. M. Peterson

I was one of those really saddened by the demise of Emerald Time, and I’m greatly appreciative of the developer for taking up the mantle. There is a lot of information here, and lots to figure out. The only thing I could possibly ask for: sound effects. Having multiple iOS devices with ~ms synchronization emitting a 1- or 5-second tone was a great tool for understanding how location differences could be “heard”. Again, my thanks! UPDATE: thanks for the ticking, and the voice!
Great App!
Aug 9
G77777777777777777!
Works perfectly! Thank you. I do ntp redirects in my environment was hoping it would help me know if it was my internal ntp or external that was the actual resolver. Not sure if there is a way.
Great App!
Aug 9
G77777777777777777!

Works perfectly! Thank you. I do ntp redirects in my environment was hoping it would help me know if it was my internal ntp or external that was the actual resolver. Not sure if there is a way.

RADIO TIME CODES, SPELLED OUT A clock sold as "atomic" is really a radio, listening to a distant station that spells out the time one second at a time. TrueOffset now plays those codes, timed to the true second, and shows each one being read as it arrives: WWVB, DCF77, MSF, JJY (40 and 60 kHz), and BPC, plus the codes of WWV, WWVH, CHU, and Australia's VNG. That makes fourteen signals in all, each built from its station's published sound and timing. None of them is a recording. - Set a Radio-Controlled Watch (beta): lay a watch on the speaker and let it listen. It has set a Citizen Eco-Drive in Australia, far out of WWVB's reach. If you try it, tell us how it went. - DCF77 weather: switch it on, and your local forecast rides in the code's weather seconds, the way Germany's station once sent its own. TrueOffset asks for your approximate location only when you turn this on. - The Lincolnshire Poacher: a shortwave mystery, not a time signal. It plays only when you ask for it. ALSO NEW - Help in the app: what an offset is, why clocks drift, what each screen shows, and what TrueOffset asks for and why - On Wi-Fi, a note says how much of the offset can be network delay - A new default reference, ntp.trueoffset.app, a Safran SecureSync 1200 with its own rubidium atomic clock - The Quality ranking names the steadiest of three or more servers - Clearer, higher-contrast text throughout - Public servers now get one request per poll, as their operators ask - TrueOffset is now on the Mac, too, free in the same App Store listing

Version 1.4 4d ago

Data Not Collected

The developer does not collect any data from this app.

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Accessibility

Information

Seller: Richard Bollar
Size: 4.3 MB
Category: Utilities
Compatibility: Requires iOS 17.6 or later.

iPhone
Requires iOS 17.6 or later.

iPad
Requires iPadOS 17.6 or later.

Mac
Requires macOS 14.6 or later and a Mac with Apple M1 chip or later.

Apple Vision
Requires visionOS 1.3 or later.

Apple TV
Requires tvOS 26.2 or later.
Languages: English
Age Rating: 4+

4+

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