"Mamayâ" is "later today" while "mayámayá" is "a few minutes from now" or "a little later".
"Si Tom ay pumasok sa trabaho. Ang uwi niya ay mamayâ pa". = Tom went to work. He's coming home later yet.
"Si Tom ay pumunta lang sa tindahan sa kanto. Nandito na 'yun mayámayá = Tom just went to the corner store. He'll be here in a short while.
In this example, "mayámayá was used because the idea being conveyed is that right after frying the fish, it will eaten for lunch. Without mentioning it, the time that Mary is frying the fish will be understood to be just before lunch time.
Had this instead used "mamayâ" and Mary was frying the fish close to lunchtime, it would most likely be understood that the fish is to be eaten for supper, i.e., later today yet.
Formal Rank: #1790 Casual Rank: #913 ** A lower rank means the word is used more frequently. For example, rank #1 would be the most frequently used word.
Method: This script ranks all words by frequency using both formal sources (mostly newspaper articles) and informal sources (a combination of over 100 hours of transcribed audio, internet comments, and amateur fiction writing) to roughly determine whether a word is used more frequency in casual or formal contexts.