BED is right, that is the normalized score. There are some trick to get a high score:
- Population is very important. Open the WB and reduce the size of your largest city, it will make a large difference.
- Territory is also important, but usually it's not so easy to gain lots of cities close to the deadline.
- Technology is not important, the gain is very low.
- Wonders contribute too but I'm not so sure how much. Same story as territory however, you aren't going to finish all wonders just before the deadline.
So, how to raise score? Some turns before the deadline, emphasize food. As many cities as possible must grow as large as possible. If the third UHV three turns left, the city should grow within 3 turns. Also, try to build culture in these cities, one cultural expansion might mean a lot, especially for early civs like Babylon or Egypt. Try to balance this with technology, so that you finish a tech AND pop some cities' borders. Note that your finalized score is not calculated after you hit the "next turn" button, but after all calculations are done. So, a city that grows in one turn WILL contribute more to your score.
So, does it matter?
Yes, it does. Open end UHVs like the Viking one can be postponed until there is nothing that increases the following turn. In 1.181, I won in 1530 with a ~7600 score (with squatting of course, without Brittain it wouldn't be near that). However, London, Inverness and Kalmar were growing really quickly, so I decided to wait a little longer, next turn I got ~7800. In the end, I finished in 1545 with a score of over 8400. Earlier civs can easily get a larger increase.