The NOC you are using as your main occupation, will have a minimum qualification mentioned for it( as declared by CIC). If that qualification if a bachelor's or undergraduate degree then you can give the date of your undergrad. That's what I know, might wanna wait for others to confirm
NOC 0124 says "A university degree or college diploma in business administration or in a related field with a specialization in sales or marketing and Several years of experience", so should I choose 2013 instead? It's when I started working for the job I claim the points for and got that 'several years of experience' in similar positions.
I see this question surfaced many times on this forum and the answers are slightly different based on individual case.