Start the learn how to use "CLOCK" in org-mode. I love it. You can do
the clock in and clock out. Then you got your simple report on how
much time you spent on your little tasks or the whole project. That's
so easy and wonderful.
After 3 days, I figure out that I spend 2.05 hours on my current
project. Hope me boss would never read this post. The "CLOCK" will be
part of my self management tool from now.