how does someone gain time in 1 min games

Why is it that in some one minute games the other player gains time with every move? 

but i'm playing normal 1,3,5,10 minute games not 1/2 or any other dash games

By  using a TARDIS.

You mean that Dr Who is cheating here?

Sometimes a lag will keep you from knowing the "real" amount of time on the clock. For example, it might seem like your opponent is taking 5 seconds, but then all of a sudden he gets 3 of those seconds "back" and now all of a sudden you lose 3 seconds out of nowhere! It turns out that it has been your move for those 3 seconds where it seemed like his clock was still ticking (if there is a 3 second lag, then he actually took 2 seconds, instead of 5 seconds), but the server didn't tell you in time.

in 1/0, you don't actually gain time, but lag can cause the appearance of someone gaining time. What is really happening is the server is readjusting to the correct amount of time on the respective clocks.

This just lost me a game. Someone only had 2 seconds remaining, and I sacced pieces to get the time win and he ended up checkmating me after 10(!!!!) moves with 8 seconds leftover. What the heck!