Workdays rhymes with:
weekdays, birthdays, ceredase, faraday's, holiday's, holidays, holliday's, hyundai's, hyundais, newsday's, nowadays, sundae's, sunday's, sundays, traveldays, tuesdays, velagrande's, wednesdays, weekdays, yesterday's, yesterdays
Workdays sounds like:
workouts, worksheets, worst-case, wright's, wrights, wrists, wristwatch, wristwatches, wursthaus