Timelapse is a fun way to spend your time and to create something that people love to see. Shooting at day or at night separately is not a problem, but what does become a problem is when you try to shoot from day to night or from night to day. If you have not done it before it can seem complicated and chances are you will screw up the first couple times trying to figure it out.
Photographer Preston Kanak recently released an amazing full length and very detailed tutorial on shooting timelapse for day to night or night to day. The video itself is over an hour long so you will want to wait to watch it until you have some free time. But the video is very well done, and covers the three most popular methods that you can use then you are wanting to shoot timlapse from day to night.