The clock is a feature that was introduced in Grand Theft Auto III, and has been present in every Grand Theft Auto game since. Although relatively unimportant to the player in most games, the clock plays an important role in the realistic environment of the series.
As Grand Theft Auto 1 takes place exclusively during the day and Grand Theft Auto 2 takes place exclusively at night, there is no requirement to know the time, and no clock is present in these games. GTA III introduced a new weather system, in addition to a daily solar cycle. The clock is displayed in the HUD at the top-right of the screen in all GTA III Era games, and is responsible for the progression of the solar cycle, and triggering events such as turning on street lights and vehicle headlights, which happen at the same time every day. The clock displays the time in 24-hour time, and progresses at one in-game minute per real-life second; therefore one in-game hour takes one real-life minute, and one in-game day takes 24 real-life minutes. In addition, some missions can only be initiated during a specific time frame.
In GTA IV the clock was slowed to one in-game minute per two real-life seconds, with one in-game hour taking two real-life minutes and one in-game day taking 48 real-life minutes. As the HUD was made much cleaner in GTA IV, with all features except for the radar (which now also displays the player's health and armour) only appearing when required, the clock has been removed from the HUD - Although it is now accessible from the player's phone, and in the pause menu. In addition, the clock also now includes the day of the week, which is important as certain events such as dates are scheduled for particular days.
The quick speed that the clock progresses can in some cases improve the realism of the game, and in other cases distract from realism. For example, although it only takes a couple of real-life minutes to travel from one side of the city to the other, the clock presents this as a couple of hours. However, it also shows events such as phonecalls, simple missions, dates, etc. which should take somewhere from a few minutes to a couple of hours as taking several hours or days. In addition, timed missions use minutes, which the clock treats as hours. One example of this is the mission Shakedown in Grand Theft Auto: Vice City, where Tommy Vercetti says I'll be back in five minutes and the player receives a five minute time limit, in-game this is actually five hours.
As some missions can only be initiated during a particular time frame, the player needs to either wait for this time, or do something else in the meantime. Waiting may be a long time, but doing something else could result in missing the next opportunity. In addition, some events in GTA IV such as dates are scheduled for a particular day, and if missed, result in a negative outcome rather than simply reappearing the next week, making them even more difficult to arrive at. However, the game seems to be lenient by initiating the mission quite some time before or after the scheduled time. two ways to progress time is to save the game repeatedly, which progresses the clock by six hours each time, or enter spray shop which progresses the clock by three hours each time.
- When meeting with friends in GTA IV, they will say I'll see you in an hour, and the game will prompt the player that they will wait for one hour. Depending on how far the friend is located from the player's current position, arriving in one hour may be impossible. However, the friends seem to wait longer than one hour before complaining that the player is late. Also, the player can arrive before the hour (even immediately after calling them) with no issue.