Hello team! 
For the different teams that use Hubspot, the gain would be considerable to be able to know the day of the week that corresponds to a date.
For example, if a prospect arrives on a Sunday, we can predict different communications from a prospect who arrive during opening hours.
In summary, the idea, would be to have either a property, an automation solution to either bring up the day of the week associated with a calendar property.
Thank you 
Have a good day