Can I prevent an iOS user from changing the date and time?

Question

I want to deploy managed iOS devices to employees of the company, and the app they will use will timestamp data that will be recorded locally, then forwarded. I need those t

Answer 1

There doesn't appear to be any way to accomplish what you're asking for. There doesn't seem to be a way to stop the user from being able to change the time. But beyond that, even if you could prevent them from changing the time, they could let their device battery die, then plug it in and turn it on where they don't have a net connection, and their clock will be wrong until it has a chance to set itself over a network. So even preventing them from changing the time won't guarantee accuracy.

What you could do is require a network connection to record values, so that you can verify the time on a server. If you must allow it to work without a net connection, you could at least always log the current time when the app is brought up and note if the time ever seems to go backwards. You'll know something is up if the timestamp suddenly is earlier than the previous timestamp. You could also do this check perhaps only when they try to record a value. If they record a value that has a timestamp earlier than any previous recorded value, you could reject it, or log the event so that the person can be questioned about it at a later time.

This is also one of those cases where maybe you just have to trust the user not to do this, because there doesn't seem to be a perfect solution to this.