There will be three parameters. I didn't decide how they will be implemented but I think they should be allowed to change dynamically in the game.
- First turn advance - it is a analogue of first_timeout freeciv option but instead of relative time offset it uses absolute time point to be more predictable. It determines time point when there will be first turn advance after the server went to PlayingGame state from new or loaded game. If it isn't set then next turn advance will happened after turn interval time.
- Turn interval - it is a analogue of timeout freeciv option. It's a maximum interval between turn advances. It it isn't set then next turn advance will happened when all players will be ready.
- Fixed turn interval - it is a analogue of fixedlength freeciv option. If it's enabled then turn advance will happened only when turn interval would be expired. It it disabled then turn advance could happened earlier if all players will be ready.