Organize your resume around skills and positions held rather than chronology. If asked, you might politely inquire why the information is necessary, but refusing to give a date could look shifty. Better to be open about who you are and focus on your selling points as a seasoned professional: experience, proven record, depth of perspective.
Miller has written for and edited tax publications for 16 years, most recently for the accounting firm KPMG's Washington National Tax office. You can find her on Twitter, @KarlaAtWork.