Remember that “Time-Out” by definition is a “Punishment” as it is intended to decrease negative behaviors. Nowhere in the definition is it mentioned that a child must have full understanding before implementing Time-out. Sometimes parents put a child in “Time-Out” and say, “Now think about what you did wrong, and think about what else you could have done.” This is truly an admirable goal, as it changes Time-out from a technique of punishment (i.e., decreasing a negative behavior) to a technique of discipline (i.e., decreasing a negative behavior AND increasing a positive behavior). While admirable and realistic for older children, this advanced goal/level of reasoning is, of course, unrealistic for younger children.
However, just because “Time-out” is an unrealistic disciplinary technique at younger ages, it still can remain an effective technique of punishment at the younger ages (i.e., simply for use in decreasing a negative behavior). Depending on your child’s development, and depending on your opinion/preference, a general guideline is that “Time-Out” can begin when a child is able to understand a simple cause-and-effect relationship (i.e., If I push the button, the toy plays music; If I reach for the stove, I get placed in this Time-out area). To translate this “developmental” criterion to a “chronological” criterion, depending on your child’s development and your opinion/preferences, a general guideline is that an early version of “Time-out” may be implemented as early as 18 months of age.