Is there a quick way to know total reputation points at a given date, to get a sense of points earned over a span of time. One way is to manually calculate checking each date and points, I am looking for something simple stack exchange provides out of the box.
You can look at https://drupal.stackexchange.com/reputation. You would see something similar to this. (It's what I see for me.)
It shows the difference with the previous day(+20), and the reputation gained from the moment you registered on the site until that day (= 205).
If you want to see the reputation you gained between two dates, you would need to make a difference. For example, between March 4, 2011 and March 6, 2011, my reputation increased by 49 points (234-185).