How does Internet Time (without Active Directory) make adjustments to the clock? If it checks every week, and sees that the system clock is running fast, does it immediately change the clock, which I would think would be disastrous if comparing timestamps, since there would be an overlap. Would make more sense to slow the clock down until it's caught up with real time. If it works that way, are there configurations like for Windows Time Service (for AD)? Thanks.
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Windows uses the w32time service to stay in sync, which polls against an NTP source. On an AD, your NTP server is usually the default gateway but can be any other available time source. For more information on what NTP source your machine is using, you can refer to this question and its answers.
If you want a robust NTP service across your estate, consider using the same NTP source, such as one of the options available from *.pool.ntp.org https://www.pool.ntp.org/zone/uk
spikey_richie
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So I did a lot of digging, and here's what I learned...
"NTP" means several things, depending on how it's used. It's the protocol used for sending the time. An "NTP Server" answers "What time is it?". You'd think an "NTP Client" just means the one that asks "What time is it?", and in one context it is, but in another, it refers to one class of algorithms that apply the difference in time to the OS, as opposed to an "SNTP Client" (for Simple NTP) which refers to another class of such algorithms. The SNTP algorithm either applies the change right away, thus making the clock jump, or it applies the shift gradually over time. The NTP algorithm, on the other hand, speeds up or slows down the clock, sometimes applying historical data to smooth out the clock. For example, if it checks in with the NTP server every hour, and the clock is always about a second ahead, it can adjust the clock so that it runs a little slower so that when it subsequently retrieves a time, it doesn't need to change the clock's time or speed.
Windows' "Internet Time" uses the SNTP algorithm, even though it's an "NTP Client" going with that first definition. I found a lot of NTP clients that use the SNTP algorithm. I finally found a "real" NTP client. Ntp.org seems to be the place for the NTP algorithm, and they offer a *nix NTP daemon. On that site (at https://support.ntp.org/bin/view/Main/ExternalTimeRelatedLinks), I found a link for Windows implementations, and downloaded one from https://www.meinbergglobal.com/english/sw/ntp.htm that seems to fit the bill.
uncaged
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