clock problems

What would cause my opponents clock to add extra time after it reaches zero? I find this very frustrating. This happens in over 75% of my games. The clock reaches zero, then adds up to 8 seconds. This will repeat up to 5 times before finally ending the game. Any advice would be greatly appreciated.

Look up lag.

The clock you see is not always accurate. Because of lag compensation and possible disconnects on your end, the clock often is modified when the server sends the move and accurate time.

https://support.chess.com/customer/en/portal/articles/1444849-why-did-the-clock-times-suddenly-change-the-clocks-seem-broken-

The clocks you see are largely controlled by your computer.  Likewise, the clocks that your opponent sees are largely controlled by their computer.  However, it's the clock that's controlled by the server that's the true arbiter of time.

When there's a large amount of lag or partial/temporary disconnects, then it takes time for your opponent's move to register on your screen.  During these times, then your time (on your opponent's clock) and your opponent's time (on your clock) are both going down at the same time!  To compensate for this, the server may update the clock you see for your opponent's time, which leads to those sudden jumps up.

The key takeaway from this is that, while your opponent's time may go down to zero on the clock controlled by your computer, that doesn't mean that your opponent's time has gone down to zero on either their computer's clock or the server's clock.

what can I do at my end to help minimize the lag? I've purchased a new high speed router and upgraded my Internet speed. cleared my ram and checked for viruses, all to resolve this issue. I don't think my problem is the norm, is it? Have you ever lost on time with 30 seconds on your clock when your opponent hits zero? It's gotten to the point where I realize that I'll probably loose on time if I don't have 20 to 30 when my opponent hits zero, for the first time. I never know how many times there clock will be resetting.

Unfortunately, often the lag exists somewhere between your computer and the chess.com server, and there isn't much you can do about it.  However, there are some other possibilities (not all of which will be feasible for you, but I've included everything I can think of) in the order of easiest to hardest:

1.) Stop using Internet Explorer.  It is a terrible, bloated piece of software.  Most other browsers such as Firefox or Chrome stick closer to HTML standards and, thus, function cleaner on most websites.  If you've already switched to a different browser, good for you!

2.) Clear your cache/cookies.  If you don't know how to do that with your browser, you can search online with something like "clear cache firefox"

3.) Reduce the number of background processes running on your computer, this can eat up RAM and processor time (for example, some programs may have an always running service that regularly checks online for updates; while one might not be too intrusive, they can add up if you have many of them running).  Also, reduce the number of tabs you have open in your browser for the same reason.

4.) Stop playing music or videos (especially if it is streaming online) as this can eat up RAM, processor time, and/or internet bandwidth.

5.) Make sure other people on your network aren't doing #4 above.

6.) Change from a wireless connection (to your router/modem) to a wired connection.  While wireless is often more convenient, it is also a bit more prone to dropping data packets than a wired connection would be.

7.) Change your internet service provider.  I know you said you upgraded your internet speed, but if you have a crappy ISP then that might not actually do much.

8.) Move closer to the chess.com main servers (which, I believe, are in Southern California in the US).  I know this one isn't really a viable solution, but it is often the only way to help with the problem of slow/down lines that may be between your computer and the chess.com server).

Thank you for taking the time to give me such a detailed list of possible options. 1-5 and 7 have already been implemented. I play exclusively on my phone, so 6 isn't an option. I have switched from WiFi to 4g LTE to see if that helped. As far as # 8 goes, do you know any good Realtors in southern California?

Considering I don't live in or near California, that'd be a no.  Sorry.

It may be that you just need to play with a slightly longer time control, to take into account the potential for last-second lag issues, or trick your mind into treating the 30s mark as if you would run out of time there.

If you don't already, you should consider using pre-moves.  If you're sure about the move you're going to make, regardless of your opponent's move (for example, if there is a forced sequence or if your opening choice is a system such as the Colle), you can make the moves in advance and take only 0.1s per move.