Owls are creatures of the night. They get energized at night and have great difficulty waking up early. Larks, on the other hand, love to go to bed early and wake up early, ready to go! You may have noticed your baby or toddler fall into one of these two categories or show a tendency of one over the other. Now that the time has changed, you might be hoping your lark wakes up later and will be disappointed when their schedule shifts back to where it was. If you have a night owl, you are cringing at getting baby to bed earlier now that the time has shifted forward.
Developmentally, many babies go through a period of waking very early in their first year. This does NOT mean they will always be this way (for some that is sadly not the case). And, for many babies, they get “trained” to wake up early (I’ve worked with parents whose baby wakes up as early as 4!!). Since light is what cues our brain to be awake and set our internal clock, one of the bigger mistakes you can make during the first year is allowing your baby to get up much before 5:30 or 6 a.m. and continue to do it for months on end. Do NOT start your day before 6 a.m., if you can help it.
With that said, you also have to have realistic expectations and be fair to your baby. You can’t put your baby to bed at 6 p.m. and expect her to necessarily wake up at 6 a.m. or later. 11-12 hours at night is normal for babies and toddlers under 2 (after 2 is variable), with a minimum of 10 hours, so it’s important to know your baby’s tendency for night sleep (to figure that out track your baby’s sleep for 2+ weeks) and set her schedule accordingly.
My eldest son (youngest son is still up in the air) is a NIGHT OWL! It is very challenging because the bedtime routine tends to shift later and later and later if we don’t set firm limits, but too late and it used to lead to night-wakings and now it just leads to a too-early wake-up and crankiness. He is so afraid he’s going to miss something and just doesn’t want the day to end…EVER. Add to that, when he was a baby, he was mostly an 11-hour baby (until he went to one nap), so we did have a 5 or 5:30 a.m. wake-time from around 6 to 8 or 9 months (before I shifted his schedule). For awhile he was waking up after 8 or 8:30 a.m., but now he has hovered around 6:30 or 7:00 a.m. where I expect it to stay until he becomes a teenager and I have to drag him out of bed. 
Can you change a lark into an owl or vice versa?
No, not really. It’s biological. According to Ferber, they have even found a specific gene responsible! So, it’s not people’s imagination when they just aren’t “morning people” and “hate” those who bounce off the walls in the morning. However, some people’s tendency is stronger than others, so it IS possible to shift schedules at least a little bit for many babies who wake too early or go to bed too late after 9 or 10 months old. In fact, somehow I have changed into a night owl myself! I used to be a big time morning person, but I have built this entire website mostly at night (some very late ones I might add!) and I tend to have trouble getting up early these days. I blame the kids. 