Well ~Zunky~ one time my tamagotchi made babies in about a hour once. It all depends on what tamagotchi and age their on. (From what I Observed).
The Matchmaker will come 3 days/ 3 years after the adult. She will come anytime but the most common times are 10:29 PM, 2:59 PM, or 6:59 PM. Then you wait a minute.
-Locky458-