When a user hits the first and last available dates in the calendar, this is announced to them.

[timarney]

Users experience difficulty navigating through empty spots on the calendar.

(JAWS) Unavailable dates do not specify that they are unavailable.

PR https://github.com/cds-snc/ircc-rescheduler/pull/451 will take care of announcing "unavailable"

@zakkain if we're on the first or last date what should the label say?

User has enter the field: "first available date Tuesday, October 23, 2018"

User has enter the field: "last available date Tuesday, December 18, 2018"

[caycefischer]

@timarney let's replace "date" with "day" - everywhere in the UI and A11Y content, actually, to be consistent with our earlier work

other than that, looks great! 👍

[timarney]

Added this to #451