I'm just not sure we can commit to the start point of a period of a statement.  I think so much depends on the activity and verb.  A statement like "Andy earned his bachelor's degree" clearly spans an amount of time, but I'd want to know when I finished whereas a statement such as "Andy ate sushi at Takara" would probably gravitate to answer the question "what time did you get there?".  I think it is too open to put a recommendation on.