It seems like a combination of:
* "Le amo" which means "I love you" (formal, singular "you")
* "Mañana" which means "tomorrow"
The correct way to express this would be:
* "Te amo mañana" if you are speaking to a singular "you" (informal)
* "Lo/La amo mañana" if you are speaking to a singular "you" (formal)
Therefore, the closest translation to "Le amo mañana" in English would be "I love you tomorrow."
However, it's important to note that "I love you tomorrow" is an odd expression in English, so it's best to use a more natural phrase like "I'll love you tomorrow" or "I'll be loving you tomorrow".