How to aggragate data based on a keyword

I want to use Google Sheet as a time tracker. That is, in a cell I will write:

keyword_A 13:00-14:12

keyword_A is one keyword, among many, separated by space and then the starting time of the activity separated by a dash from the end time.

I want to be able designate a particular cell for the total time spent on activity keyword_A in a week, in a month, or total time spent so far.

How can I achieve this?