sum total based on when a cell was updated?

[Kanuck]

Is it possible to have a daily sum total based on when a cell was updated?

Scenario:

• I have a sheet that has a list of tasks, and I mark a task as 'Complete' the day it is done
• Each task has a point value
• I am currently manually inputting the total point value of 'Complete' tasks each day

Is there a way to Sum the value of tasks marked as 'Complete' depending on the day it was updated?
Giving this a bit more of a challenge, I do not want to have another row next to my completed tasks to input a date, which I know I can do and is my fall back if there isn't a more elegant method.

Thank you,
Kanuck

[JBeaucaire]

I imagine it will be some sort of SUMIFS() function. Or COUNTIFS().