http://schema.org/openingHours

The examples on openingHours use HTML5’s time element:

<time itemprop="openingHours" datetime="Tu,Th 16:00-20:00">Tuesdays and Thursdays 4-8pm</time>
<time itemprop="openingHours" datetime="Mo-Su">Monday through Sunday, all day</time>

The values "Tu,Th 16:00-20:00" and "Mo-Su" don’t seem to be valid according to W3C’s HTML5 or according to WHATWG’s HTML.

The examples on LocalBusiness use the meta element instead, which seems to be appropriate. The data element might also be an appropriate alternative.