yes it is..

If your baby is feeding more than 8 times a day on average during the day time, is passing urine a minimum of seven times then you can allow baby to regulate night sleep. Most babies are able to sleep longer by this age and may actually be able to sleep thru the night by the time they are six or seven months old. If above aspects are in place then you need not awaken the baby for a feed. Allow the baby to regulate his own sleeping and feeding patterns.

thank you Roopa & Sheeba :)

its normal, they drink more at one feed and sleep better... its enough to wake baby up at interval of 4 hrs, if baby does not wake on its own...

Yes . It's normal. If baby is sleeping, you only gently wake and feed. If you touch it's ears or hands... baby will be wake up for a while.