Biphasic Sleep Schedule: Day 1

I'm switching from a traditional monophasic sleep schedule to a biphasic one. After a little research, I am deciding to start with a 1.5/4.5 schedule, with the intent to drop to a 1.5/3 schedule. 

Schedule

9pm-10:30pm - 1.5 hour nap

3am-7:30am - 4.5 hour core sleep

My first 1.5 hour nap didn't actually start until 10, since I had a hard time falling asleep at a new time. It lasted until 11 when I was woken up by a phone call. I decided to stay up, as 30 min of sleep wouldn't be enough to enter REM and I would just awake groggy. Between 11pm and 3am I wasn't too sleepy, as I was able to watch a movie. I normally getting sleepy from watching movies at night. 

My first core sleep went well, as I fell asleep by 3am. I awoke once at 4am, but quickly went back to sleep. I awoke to my alarm at 7:30am. Upon waking, I was no more groggy than a typical day.

During the day I noticed I was slightly more tired than usual. (Scale from 1-10, 9 being a typical day, I was a 7). 

The 9pm nap went well, I was able to fall asleep quickly and awake easily to my alarm.

Right now between my nap and core I am at about a 6.5. I think this is good considering it's A) my first day, and B) it's currently 1:30 in the morning and dark outside.