What is byo-yomi on the zmf chess clock?

i am getting a chess clock tomorrow, but i dont know what byo-yomi is on it. its is a zmf clock

Byoyomi is a method of time control used in Shogi (Japanese Chess): you get an initial tme on the clock (like 1 hr) in which you can do as many moves as you want (including zero), and after that you get a fixed maximum time per move (like 2 min), the so-called byoyomi.

interesting that shogi players took the time to develop very intricate time control rules for their game. wonder why they did that?

Wel, considering that civilization struck in Japan much before it did in Europe or the U.S., it is likely they took the time to develop it because no one else had. So the question is more, why did they converge on this particular system?

In a pre-mechanical society I would expect hour glasses to be used as timing devices, and the most obvious way to time a two-player game with an hour glass is flip it on every turn, and do not allow either player to ever let time run out. This is pretty inconvenient for Shogi, though, where you occasionally would like to think very long to determine strategy.

Question: How did people use time clocks in a pre-mechanical society? Answer: they didn't.

Unlike chess, shogi becomes more complicated as pieces are traded, which is why it is common for this kind of time control. In some ways, it is similar to delay on the clock, except you don't get it until the initial time period is completed.

Byo-yomi is a very popular time control in Go, more on polgote.com/en/blog/time-controls-go-byo-yomi-fischer-canadian/