You are correct however you do not have to do any counting. Just click on "Regular Season Standings", change the year to 2013, click on the "Calendar" icon, choose a month/date and you will see their wins/losses at that point.
[TABLE=class: stats_table data_grid, width: 969]
[TR]
[TD=class: dg-w, bgcolor: #E1E1E1]W
20[/TD]
[TD=class: dg-l, bgcolor: #E1E1E1]L
27[/TD]
[TD=class: dg-pct, bgcolor: #E1E1E1].PCT
426[/TD]
[TD=class: dg-gb, bgcolor: #E1E1E1]GB
8.5[/TD]
[TD=class: dg-last_ten, bgcolor: #E1E1E1]L10
7-3[/TD]
[TD=class: dg-streak, bgcolor: #E1E1E1]STRK
W2[/TD]
[/TR]
[/TABLE]
Just posted this for informational purposes.