Syncing WiFi iPads with NTP Server

Question

Level 1

8 points

Syncing WiFi iPads with NTP Server

Hi, all - we have a batch of iPad minis running iOS 8.4.1. They are used to present room occupancy info outside of patient room doors - however, the current time is a prominent part of the GUI, and they're all out of sync with each other by a few minutes, which can be disconcerting. We've tried manually setting them, but drift over time seems to be significant.

I have looked at a few third-party apps that present the time from reputable time servers - but all of them say that apps are not allowed to adjust the internal system clock, so that's not a fix.

So -- the question is -- if you have an iPad without a cellular option, how do you sync it with a network NTP (Network Time Protocol) source? We can't find anything in the setup screens to answer this question, and, oddly enough, I am not seeing similar questions (with answers) anywhere.

Any assistance would be greatly appreciated.

iPad Mini, iOS 8.4.1

Posted on Aug 22, 2015 6:10 AM

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Answer 1

rccharles

Level 6

13,037 points

Aug 22, 2015 3:48 PM in response to stonea0724

You could try one of those timers and see if they work. emerald time.

Could the customer network be blocking the ntp port? Why would they do that?

You could trek out one of the devices with the wrong time and move it to a known good network. ( Works fine at my house for instance. ) Could use a hotspot on your phone and see what the device does with the time from there. Probably queries just after turning on and off time sync.

the ports 123 anyhow.

Port	TCP or UDP	Service or Protocol Name	RFC	Service Name	Used by / Additional information

123

UDP

Network Time Protocol (NTP)

1305

ntp

Date & Time preferences. Used for network time server synchronization, AppleTV Network Time Server Sync

What server is picked any how?

on Yosemite 10.10.4, apple uses.

There are lots of ping tools for the ipad.

a port scan of time.apple.com from my mac didn't reveal port 123 😐.

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Answer 2

rccharles

Level 6

13,037 points

Aug 23, 2015 10:43 AM in response to stonea0724

Left out the link:

Time is a UDP port.

TCP and UDP ports used by Apple software products - Apple Support

emerald time did good. Renamed to Time on my iPhone. Added time.apple.com as NTP server. Here's the pics:

proof of the podding

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Answer 3

stonea0724 Author

Level 1

8 points

Aug 22, 2015 2:33 PM in response to rccharles

Hi - yes, they're all connected to customer's wifi on a constant basis, and we have the time settings set to sync automatically - but it's just not happening. I had seen hints on some other threads that it might be a port thing - but not sure where to take that, if so...

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