At that stage they don't really understand the difference between day and night, however, you can help them to learn by keeping everything as dark and quiet as possible during the night (try to use dim lights if you need to change nappies or whatever) and keep the room nice and bright during the day. If you're breastfeeding that can also help as the composition of your milk changes throughout the day, which helps LO to sleep more at night and be more awake during the day. It does take a while though, and the sleep deprivation is hard!
Mine too! I feel the frustration- I tend to get a good chunky nap in too because the exhaustion is A LOT 🙃