The general opening hours for a business. Opening hours can be specified as a weekly time range, starting with days, then times per day. Multiple days can be listed with commas ',' separating each day. Day or time ranges are specified using a hyphen '-'. - Days are specified using the following two-letter combinations: `Mo`, `Tu`, `We`, `Th`, `Fr`, `Sa`, `Su`. - Times are specified using 24:00 format. For example, 3pm is specified as `15:00`, 10am as `10:00`. - Here is an example: `<time itemprop="openingHours" datetime="Tu,Th 16:00-20:00">Tuesdays and Thursdays 4-8pm</time>`. - If a business is open 7 days a week, then it can be specified as `<time itemprop="openingHours" datetime="Mo-Su">Monday through Sunday, all day</time>`.