If I remember correctly here are the growth stages for a v4 and v4.5. Note that if you pause your Tamagotchi, it will take longer. When I say "24 hours" it means that your Tamagotchi must be unpaused for 24 hours- this includes time that it's been sleeping as well. However your Tamagotchi won't evolve while sleeping- it will evolve when it wakes up the next day.
Baby -> Child: 1 hour
Child -> Teenager: 24 hours/1 day
Teenager -> Adult: 48 hours/2 days
Ability to mate via connection: 24 hours/1 day after evolving into an adult
First matchmaker visit: 48 hours/2 days after evolving into an adult, at 10.30am, 3pm and 7pm.