This article helps to show how not all tools and advice are inline with each other:

Among other bad advice is the following:

Relevant Experience
This is the section most people focus on, but they end up paying more attention to job duties and descriptions than accomplishments, Bacal says. You should include results, effects and contributions made at your former jobs, along with the company name, job title and years (not exact dates) of employment.

I have to agree with MT about including the month for simple clarification.

What are your thoughts?