Time is a major component of all Pokémon games starting with Generation II, which effects, among other things, the evolution of Pokémon, the effectiveness of certain moves, and even, sometimes, what Pokémon can be found in the wild. It even affects certain events, which may only take place at a specific time of day, or on a specific day of the week. Much like weather conditions, the time function in the games was expanded upon in each subsequent generation after its release.
In Generation II, the changing time of day was a majorly-touted feature for the games; several Pokémon were designed with this in mind, even, such as Hoothoot and Noctowl, while others would only appear in certain areas at certain times of day.
At the beginning of all three games, the clock would be set upon starting a new game, even before the player is named. The default time is 10:00 AM.
Times of day
- Morning, an hour in which many Pokémon trainers are still asleep, is when there are many Template:Type2 Pokémon scurrying out and about. For the most part, however, Morning is much the same as Day, as far as move effectiveness and Pokémon distribution goes. Morning lasts from 4:00 AM to 9:59 AM, and the rising sun tints the entire landscape with a yellowish hue.
- The daytime is the busiest time in the Pokémon world, as most people are up and about at this time. The same is true of Pokémon, who appear often and in many varieties. The landscape is not tinted at all during this time, making it seem closer to the timeless games of Generation I. Day lasts from 10:00 AM to 5:59 PM.
- A drastic change from the other two time periods, at night most Pokémon are sleeping, with the exception of a few night owls. It is at this time that players will be able to find the most sleeping Pokémon by Headbutting trees, which will give them an advantage in battle. The entire world will be colored a bluish-purple, and lights will be on in buildings all over. The longest of Generation II's three time periods, nighttime hours last from 6:00 PM to 3:59 AM.
Eevee was given two new evolutions to take advantage of the changing time, Espeon, which it would become if its Happiness maxed out during the morning or day, and Umbreon, which it would become if its Happiness maxed during the night.
Days of the week
When the PokéGear is first received, the player's mother will ask him or her to set the day of the week as well. This affects several things, such as the National Park's Bug-Catching Contest and which of the Weekday Siblings appears, though not much else.
Unlike Generation II, Generation III had no separate time periods, or even an ability to check the time in-game unless the player traveled all the way back to Littleroot Town, where they had set an analog clock at the beginning of the game. Also unlike Generation II, the time-based events were very few and extremely far between, with the clock mostly running to keep track of the growth of planted berries (although this was not completely foolproof). There was, however, some premise in the games. For example, Shoal Cave's water level would change every six hours, at 3:00 and 9:00 AM and PM. Just the same, Eevee would be able to evolve into Espeon during AM hours, and into Umbreon during PM hours. The loss of such a beloved feature from Generation II angered many, however, their hopes for its return would soon be answered by the next generation.
In Generation IV, the time function returned in full force, to the joy of many. This time, however, it would run off of the Nintendo DS's system clock, though it would return many of the functions originally released in Generation II. Many new Pokémon also now would evolve based upon the time of day, though not like Eevee would, i.e., having a different evolution for each time period. Instead, they would evolve only during the time period specified. The three time periods from GSC came back as well, adding an afternoon time period between day and night, and a late night period between night and morning. Also running off of the DS's clock is the same day-of-the-week function from the Generation II games, though this time, by running off of the DS, it keeps track of the date of capture of every Pokémon. However, it does not have much other function.
Times of day
- Like Generation II, morning tints everything a yellowish color.
- Everything takes on its natural color during the day.
- During the afternoon, the sunset bathes the world in an orange light.
- Much like its Generation II counterpart, the world is dark, but pockmarked by the bright lights of buildings.
- Late night
- As people go to bed, the lights are turned off.