Do baby's sleep cycles change at night?

Do babys sleep cycles change at night? Ive heard 2 things. First being that babys night time sleep cycles are 2hrs long compared with 40-50m during the day sonif they wake after 2hrs they either cam connect cycles or they are over tired/hungry/uncomfortable. Second being that babys night time cycles are the same length as the day (40m-50m) so if your baby sleeps longer than 40m-50m they are able to connect cycles. Which is true? I know that around early morning e.g 5am they are in a lighter sleep as the melatonin starts to wear off ready for morning wake up. Going through a few night wakenings with our 7.5m old, so trying to figure out if its genuine hunger (he does eat enough in the day and falls back asleep within 5min after a feed during night) habbit, overtired, or cant connect cycles.