"Time" is actually determined by Egg cycle completion, which is determined by in-game steps or biking. An Egg cycle is a counted number of steps that activates breeding-related programs in the game. One Egg cycle lasts 256 steps in the second and third generations, 255 steps in the fourth generation, and 257 steps in later generations. When the game reaches the end of an Egg cycle, it does a few things: the step counter for the cycle is reset to zero, the game randomly decides if an Egg is to be found at the Day Care (if compatible Pokémon are present in the Day Care at the time), and all (or only a few) Eggs currently in the player's [[party]] have their Egg cycle count reduced by one. If the Egg cycle count for an Egg reaches zero after being reduced (in the second and in the fifth or later generations) or is zero when it would be reduced (in the third and fourth generations), the Egg will begin to hatch. Prior to the fifth generation, if an Egg hatches, the game will not subtract an Egg cycle count from the rest of the Eggs after it in the party, ensuring that no two Eggs can hatch at the same time. In the fifth generation and later, if more than one Egg reaches zero at the same time, the first Egg hatches immediately while the rest hatch in order each time the player takes another step.