Answer the following Q with stream of consciousness. Passage: The Battle of San Jacinto, fought on April 21, 1836, in present-day Harris County, Texas, was the decisive battle of the Texas Revolution. Led by General Sam Houston, the Texian Army engaged and defeated General Antonio Lopez de Santa Anna's Mexican army in a fight that lasted just 18 minutes.

Question: Based on this passage, when did the battle of san jacinto start and end?
To answer the above question, the relevant sentence is: The Battle of San Jacinto, fought on April 21, 1836, in present-day Harris County, Texas, was the decisive battle of the Texas Revolution. Therefore, the final answer is April 21 , 1836.