I would remove all dates from your resume. This is an acceptable practice. By doing so you remove any problems with so-called gaps, and the focus is on your skills. If the interviewer wants to know about how recent the experience is, then answer the question honestly and truthfully, but there is no need to volunteer the dates, especially when doing so might create awkward looking gaps in your resume.
P.S. When reading your question it sounds like there's no gap in work. Do you not put your freelance work on your resume, giving the appearance of a gap, or does this potential employer want to call every single previous employer to check on you? If the latter is the case then I'd be concerned with that work environment.
EDIT: To be clear I'm not saying you should always remove dates from your resume. However if the dates are not conducive to the story you're telling and would paint an inaccurate picture of your skills and experience it is ok to leave them out. Each resume is different, some call for dates some don't. Some list full job histories, some don't. Some focus on education, while others focus on volunteer work. The point is that each resume is about telling a story, and to make sure that it tells an accurate story. Don't lie, but that doesn't mean you have to include all information about everything you've done on your resume. Nobody does. We all leave things out because they would hurt us when we know they shouldn't but also know the employer won't know that. So just be selective and include what helps you get the job and what helps the employer get the most accurate picture of you.