I keep one entry per day in my excel spread sheet, but I also keep a detailed notebook with the session by session results.
For the excel spread sheet, I enter the following data:
Date,
City,
Hours played
Won loss
Cumulative total win/loss
Cumulative total hours played
Then I compute:
Tips
Total win + tips = actual amount won at the game
Average length of winning day
Average length of losing day
Average amount won on winning day
Average amount lost on losing day
Standard deviation per hour (100 hands m/l)
EV per hour (100 hands m/l)
But, this is just my way of doing it...
--Mayor