SharePoint 2010 - define your work week (and weekends)

Community,

Is there a way to setup my regional settings to define my work week and weekends with different start and end times?

For example, my engineering team works the following hours...

1. Monday - Friday = 1pm to 9pm (EST)
2. Saturday = 9am to 5pm (EST)

From my limited knowledge, the regional settings only allow me to set either or, not both.

Thank you!