who can call for the clock in a tournament?

[Diamond Lie]

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TDA Rule 5 - Calling For A Clock

Once a reasonable amount of time has passed and a clock is called for, a player will be given a maximum of one minute to make a decision. If action has not been taken before time expires, there will be a 10-second countdown. If a player has not acted by the time the countdown is over, the player’s hand will be dead.

[/ QUOTE ]

What exactly is a reasonable amount of time lol