Add bizhours function

[bbrewington]

It would be nice to have a function bizhours that calculates the number of working hours between two Datetimes.

There are a couple ways to define a schedule, as I see it:

1. Vary by workday: Data frame of weekday, hour, workhour flag
2. Does not vary by workday: provide a workinghours argument in addition to the weekdays argument

[wilsonfreitas]

Hi @bbrewington this seems really interesting!
This is not clear if this must be implemented in the Calendar or in a new structure or class.

I imagine something like this:

bizhours("2017-07-01 12:00:00", "2017-07-06 14:00:00", "Brazil/ANBIMA", "HoursSchedule")

Using ISO datetime or POSIX objects as arguments.

Does this make sense?

[bbrewington]

I think that would work fine. How would the hour schedule be structured?