After the milk comes in (if breastfeeding), or after the first 2 days (if bottle feeding), it is common for new babies to 'bunch up' their feeds at certain times, and spread them out over others, in a 24 hour period. The most widespread pattern for newborn babies involves moving 'in and out' of various phases, every 24 hours or so.
The phases usually consist of:
A 'regular phase'. A 'regular phase' is when the baby has 2 or 3 feeds that are spaced at the 'expected' 3 to 4 hour intervals. Not many babies do this consistently over a 24 hour period in the first 8 weeks, but may have 2 or 3 breaks like this over 24 hours.
A 'wakeful phase'. The 'wakeful phase' is when the baby is feeding frequently, (or constantly) every 1 to 2 hours. This could last an average of 2 to 6 hours, and can be at any time of the day or night. The wakeful phase is often accompanied by the baby being unsettled and/or crying. Many women refer to this time as 'the mothering hours' or the 'feed, vomit, poo' merry-go-round (that never seems to have an end sometimes!)
A 'sleeping phase'. The 'sleeping phase' usually comes after the wakeful phase ends. The baby (and hopefully the mother) will usually fall into a deep sleep for about 4 to 6 hours or so, getting back to the 'regular phase' again.
In the first few weeks, most babies will not know the difference between night and day. This means that their 'wakeful phase' can often be at an inconvenient time for you (for example from midnight till 4am), with the sleeping phase being when the rest of the household is awake (from 6 am till 11am!) This is very normal, until your baby's
biorhythms slowly adapt.
Over time, the wakeful phase will slowly move around to occurring in the early evenings (usually somewhere between 4 and 10 pm). These tend to be the typical 'mothering hours' as the baby matures.