When you have a set of data, there is a high chance that it is incomplete. Not only does the data, outside the given range not exist, but also values between known ones are missing. But what if your work relies on that missing data?
You can use interpolation and extrapolation to fill the missing gaps in your data set.

On the 20th March 2015, there was a partial sun eclipse. I wanted to make a timelapse. I put my camera on a tripod, placed the sun in the lower left corner of the display and started the timelapse mode which made a photo every 5 seconds. After 20 muinutes, I realized that the sun will soon move out of the picture.