Option exercise date is the date on or before which an option holder can exercise their right to buy (call) or sell (put) the underlying asset at the strike price. American-style options can be exercised any time before expiration, while European-style options can only be exercised on the expiration date. Exercise timing significantly affects option value and strategy outcomes.

Exercise decisions depend on intrinsic value, time value, dividend dates, and carrying costs. Early exercise of American options is rarely optimal for calls on non-dividend paying stocks but may be beneficial for puts or dividend-capture strategies. Understanding exercise timing helps optimize option strategy performance and avoid value destruction.

Real-world example: An Apple call option with $150 strike expires on Friday when Apple trades at $160, requiring the holder to exercise by market close to capture the $10 per share intrinsic value or face option expiration worthless.