Fix the server clock

Those are fair suggestions for mobile. I'm going to think on that. 

it happens with me also but now I have realised that it was because of my bad Internet connection .

Erik: Thanks for the consideration.  

Although my initial comment on this thread was a bit whiney and non-technical (due to the fact of losing several games purely to 'lost time') I can provide ideas (if you're interested in any input) based on my own development of client/server apps.

Being a software engineer myself I completely understand the slippery slope of trust in any application hierarchy.   As usual, it's always tradeoffs.  And in a public-facing application such as this, I think in general it's a good idea to do whatever is possible to 'enhance the user experience' as much as possible.

And 're: cyberwarior'.  Yes, it happens when anyone has 'bad internet'.  That's the whole point.  This doesn't affect you if you have a perfect connection, and there's no major delay/latency between you and chess.com.  But obviously this is not always the case!  So yeah... The point being, if you have a 'slightly' bad connection of any kind, you should not be penalized.

I just watched my clock drop by 15 seconds at a clip while it was still my opponents turn.

Also, I had about 17 seconds left, set up a premove.  And then by the time it was my turn the game was over and I was out of time.

Full bars on wifi.  90ms ping to chess.com

I give up.   Lichess has this figured out already.  This is ridiculous.

https://www.chess.com/live/game/2182573378

3-4 Bars of chess.com connectivity throughout most of the game, especially the end game.   WIFI Signal at full bars.

My clock went from 1:30 down to 17 seconds between three moves towards the end.  I watched my clock drain as it was still my opponents turn.

A search for Lichess disconnects reveals a lot of similar threads. Good luck to you.