4 ms·

Did iOS 9 set millions of iPhone clocks to the wrong time?

raspasov 11y ago
Mine is 5.5 seconds ahead!
mrks_ 11y ago
Easier way to check if your phone is affected: http://time.is http://time.is My iPhone running iOS 9 (updated launch day) is 17 seconds ahead!
- jameswilsterman 11y ago
  Thanks. I feel like this issue is strangely underreported.
- toufka 11y ago
  Laptop (OSX 10.10) is 'exact' Old iPhone 4 (iOS 7) is 0.2 seconds behind, +/- 0.18 second error - 'good'. New iPad (iOS 9) is 2.1 seconds ahead, +/- 0.08 second error - 'bad' (through 3x reloads, same amount each reload). Seems to be an issue...
- cimbal 11y ago
  New iPad (iOS 9.1) was 3.6 seconds ahead. I disabled automatic synchronization, set the clock manually and then turned synchronization back on. Everything looks fine now, with only +/- 0.044 seconds error. Too bad i don't know if turning it off and on again would have worked too.
sigmar 11y ago
Any idea why the time is incorrect? Does forcing a synchronization of the clock in the settings fix it? (Don't have an iphone, so I'm unsure if such an option exists)
- mlchild 11y ago
  Not sure why it's incorrect, and turning on/off the automatic synchronization in Settings doesn't seem to do anything.
joezydeco 11y ago
I have a little desktop clock that synchronizes to WWV every night. My iphone5S is about 6 seconds fast.
PhantomGremlin 11y ago
I monitor ntp activity from the computers and iPhones on my home network, so I have a good understanding of how Apple does this, at least on OS X and iOS 8.4, at least when WiFi is available. It's simple ntp. The computers ask DNS for time.apple.com, while the iOS devices ask for a similar domain, time-ios.apple.com. From that point both types of devices make ntp requests. What I do on my firewall is redirect those requests to my local ntp server, this saves on external ntp traffic. time.apple.com resolves to 12 different IP addresses, all on Apple's 17.0.0.0/8 network. It's easy to see, just issue the following command and you'll see all of them: ntpdate -quv time.apple.com These servers are pretty darn good, they're stratum 1, they're distributed all over the world. Time from them seems to agree to within milliseconds of each other. The iOS address only seems to resolve to 3 places, but those also agree to milliseconds of each other. Given that, I can think of at least 3 different error scenarios: 1) Apple broke something in actual ntp implementation in iOS 9. 2) One of the iOS ntp servers is goofing up. Unlikely since I'm sure Apple doubtlessly has lots of monitoring for errors like that. 3) Without WiFi available, iOS relies on the cell carrier for time services. Of course, the operation of the cell network depends on all phones knowing the exact time, but that probably doesn't carry over to something ancillary like ntp. Perhaps a carrier's ntp server is borked? To resolve this it would be interesting to know and try: does the problem happen only on WiFi? does the problem happen only on cellular? does the problem only happen with a specific carrier? if WiFi, use something like tcpdump to monitor the actual packets to see if any obviously bad time is being served Why would anyone update to 9.0.0 anyway? New software always has teething problems.
- jameswilsterman 11y ago
  For me the problem seems to affect both WiFi and LTE (on Verizon). What's crazy is that my clock seems to be getting worse. It's gone from 5s off to now ~20s off since I've upgraded.
  - AlphaSite 11y ago
    It's gotten to a minute and 2 s now.
- 11y ago
mookie 11y ago
Mine is 35 seconds fast! iPhone 6 on verizon

Mine is 5.5 seconds ahead!

mrks_ 11y ago

Easier way to check if your phone is affected: http://time.is http://time.is My iPhone running iOS 9 (updated launch day) is 17 seconds ahead!

jameswilsterman 11y ago
Thanks. I feel like this issue is strangely underreported.
toufka 11y ago
Laptop (OSX 10.10) is 'exact' Old iPhone 4 (iOS 7) is 0.2 seconds behind, +/- 0.18 second error - 'good'. New iPad (iOS 9) is 2.1 seconds ahead, +/- 0.08 second error - 'bad' (through 3x reloads, same amount each reload). Seems to be an issue...
cimbal 11y ago
New iPad (iOS 9.1) was 3.6 seconds ahead. I disabled automatic synchronization, set the clock manually and then turned synchronization back on. Everything looks fine now, with only +/- 0.044 seconds error. Too bad i don't know if turning it off and on again would have worked too.

sigmar 11y ago

Any idea why the time is incorrect? Does forcing a synchronization of the clock in the settings fix it? (Don't have an iphone, so I'm unsure if such an option exists)

mlchild 11y ago
Not sure why it's incorrect, and turning on/off the automatic synchronization in Settings doesn't seem to do anything.

joezydeco 11y ago

I have a little desktop clock that synchronizes to WWV every night. My iphone5S is about 6 seconds fast.

PhantomGremlin 11y ago

I monitor ntp activity from the computers and iPhones on my home network, so I have a good understanding of how Apple does this, at least on OS X and iOS 8.4, at least when WiFi is available. It's simple ntp. The computers ask DNS for time.apple.com, while the iOS devices ask for a similar domain, time-ios.apple.com. From that point both types of devices make ntp requests. What I do on my firewall is redirect those requests to my local ntp server, this saves on external ntp traffic. time.apple.com resolves to 12 different IP addresses, all on Apple's 17.0.0.0/8 network. It's easy to see, just issue the following command and you'll see all of them: ntpdate -quv time.apple.com These servers are pretty darn good, they're stratum 1, they're distributed all over the world. Time from them seems to agree to within milliseconds of each other. The iOS address only seems to resolve to 3 places, but those also agree to milliseconds of each other. Given that, I can think of at least 3 different error scenarios: 1) Apple broke something in actual ntp implementation in iOS 9. 2) One of the iOS ntp servers is goofing up. Unlikely since I'm sure Apple doubtlessly has lots of monitoring for errors like that. 3) Without WiFi available, iOS relies on the cell carrier for time services. Of course, the operation of the cell network depends on all phones knowing the exact time, but that probably doesn't carry over to something ancillary like ntp. Perhaps a carrier's ntp server is borked? To resolve this it would be interesting to know and try: does the problem happen only on WiFi? does the problem happen only on cellular? does the problem only happen with a specific carrier? if WiFi, use something like tcpdump to monitor the actual packets to see if any obviously bad time is being served Why would anyone update to 9.0.0 anyway? New software always has teething problems.

jameswilsterman 11y ago
For me the problem seems to affect both WiFi and LTE (on Verizon). What's crazy is that my clock seems to be getting worse. It's gone from 5s off to now ~20s off since I've upgraded.
- AlphaSite 11y ago
  It's gotten to a minute and 2 s now.
11y ago

mookie 11y ago

Mine is 35 seconds fast! iPhone 6 on verizon