Act Happy Day is observed on the third Monday in March and encourages individuals to adopt cheerful behaviors to uplift their mood and the atmosphere around them. Founded by Dr. Dale Anderson in 2004, the day promotes the idea that happiness is not just a feeling but also an action that can influence others. Common customs include sharing genuine compliments, performing random acts of kindness, hosting joyful gatherings, and engaging in laughter therapy. Activities can range from simple gestures like holding the door open to organizing game nights or watching comedies with friends. The day emphasizes the contagious nature of moods and the power of small, joyful actions to create a positive impact in social interactions.