Cluster Feeding

JC1009

my 3.5 week old only eats about 2 oz (he's 9.4 lbs) every 2 hours.  He's like clockwork.  Is this a good amount and at what point do they start increasing the amount?  I hear about cluster feeding at night so the baby sleeps longer.  I'm at a loss at how to achieve this.  Do you feed him his normal amount (2 oz) then give him another 1 oz or 2oz each hour until bedtime?

 TIA