+ Clock

The + Clock, originally known as simply Clock, is an item that appears in a number of Mario games, where collecting it gives the player more time to complete a task, such as reaching the Goal Pole at the end of a level.

Super Mario Bros. Special
The item first appears in Super Mario Bros. Special, simply called "Clock," where it adds 100 units to the timer. It is only found in World 8-3.

Super Mario Galaxy 2
+ Clocks appear in Super Mario Galaxy 2, as a green stopwatch with the hand pointed upwards. These appear in several Speedy Comet missions and add ten seconds to the player's time limit, which starts at either twenty or thirty seconds. The player must collect these in order to complete the level. They appear only in the Speedy Comet missions for Sky Station Galaxy, Bowser's Lava Lair, Bowser's Gravity Gauntlet, Bowser's Galaxy Generator, and Stone Cyclone Galaxy.

Super Mario 3D Land
+ Clocks reappear in Super Mario 3D Land with a similar purpose. They appear in two different colors: cyan and green. Cyan clocks refill 10 seconds of the time limit, while green clocks refill 100 seconds. They are rarer, especially the green clocks, than they were in Super Mario Galaxy 2. Certain courses in the Special Worlds start with only 30 seconds, and require the player to either collect cyan clocks or defeat certain cyan clock-holding enemies to keep the time limit from expiring.

Additionally, the icon for the time limit in this game is a + Clock.

New Super Mario Bros. 2
Both green and cyan + Clocks also appear in the Coin Rush mode of New Super Mario Bros. 2. The cyan clocks still add 10 seconds, but the green clocks add 50 seconds to the time limit when collected.

Super Mario 3D World / Super Mario 3D World + Bowser's Fury
Green and cyan + Clocks both reappear in Super Mario 3D World and Super Mario 3D World + Bowser's Fury, where they work as they did in Super Mario 3D Land. Both types of + Clocks reward the player 100 points.

Yoshi's Safari
Clocks reappear in Yoshi's Safari as items that add one minute to the player's timer when used during boss battles only. If not used during the battle, the player earns 6,000 bonus points to their high score.

Mario vs. Donkey Kong: Minis March Again!
Clocks sometimes spawn in Mario vs. Donkey Kong: Minis March Again! in Donkey Kong levels, where they can be collected by shooting a Mini Mario toy into them. Blue clocks add 30 seconds to the timer, while the gray fuming variety take 30 seconds away.

Mario vs. Donkey Kong: Mini-Land Mayhem!
Clocks spawn in Mario vs. Donkey Kong: Mini-Land Mayhem! in Donkey Kong levels and in minigames. In Donkey Kong levels, they sometimes appear when the timer drops below 180 seconds. Collecting a clock in a Donkey Kong level adds 30 seconds to the timer, while collecting a clock in a minigame adds 10 seconds.

Mario and Donkey Kong: Minis on the Move
In Mario and Donkey Kong: Minis on the Move, depending on the mode, the player can earn extra time. One way to earn time is to create a loop with the tiles as the Minis are running on it. In Giant Jungle, there are + Clocks scattered around the level.

Super Mario Party
Green + Clocks appear in the River Survival mode of Super Mario Party, where each one adds three seconds to the timer when collected. The Hard mode features blue + Clocks which add one second to the timer when collected.

Yoshi's Crafted World
Similar, deep-blue time boosters with constantly spinning hands appear in Yoshi's Crafted World, specifically in the level Hoop-Jump Hop. They add 30 seconds to the timer.

Dr. Mario World
Some yellow + Clocks appears along with capsules and diamonds during Special Attack of Dr. Wario in Dr. Mario World.

Other appearances
In prototype builds of Super Mario World 2: Yoshi's Island, clocks were used to replenish the Countdown Timer, but were replaced by Stars by the final game. The same goes for what would become the 10 Point Star and 20 Point Star.

Super Mario 3D Land

 * Instruction manual: "Increases the amount of time remaining."

Super Mario 3D World

 * Instruction manual: "Grab one of these to add extra seconds to the timer."