The exact origin of this greeting is not documented, so it is best known through how it circulates online as a short WhatsApp audio. Short Spanish greetings like this travel quickly between friends and family chats, where they are saved, forwarded and reused as a personal alternative to typing good morning. The appeal is the specific name Bambaro, which makes a simple feliz día feel directed at someone in particular. That specificity is why people keep dropping it into everyday conversations and light edits long after first hearing it.