Have you reviewed your company's NTP configuration recently? Is it secure or can it be totally PWND? Let's talk about the "Why" and then we'll get to the How to configure NTP.
First, what does NTP do? It provides the same time, enterprise wide. What happens if you log into a router on some distant continent that does not have the correct time? If you are trying to correlate logs, good luck! You are going to need more than a slide rule to match things up.
Second, if a person with ill-intent decides to hack into your network, what better way to cover their tracks than to completely mess up your time settings. Imagine if the clocks were different on every device, there's no way you would be able to correlate what happened and when.
So, that is why you need to have synchronized time. Take the bull by the horns like this is a military operation. Now let's talk about the how.