I agree with Aarismom (she always beats me to the punch with great advice :wink: )
Depending on your babies temperment you may need to increase wake time more gradually. I believe Angel and textbook babies can handle a 15 min adjustment, whereas you may have to be more gradual with spirited, touchy, or grumpy babies, trying 5 minute increments.
good luck, let us know how it goes.