Days of the week when the merchant typically operates, indicated via opening hours markup.

Defines the day(s) of the week on which a recurring [Event](https://schema.org/Event) takes place. May be specified using either [DayOfWeek](https://schema.org/DayOfWeek), or alternatively [Text](https://schema.org/Text) conforming to iCal's syntax for byDay recurrence rules.

The day of the week for which these opening hours are valid.