I did a little search for you. Below are several Pega 7 Calendar related features. It may provide you some help.
Data-Admin-Calendar stores an instance keyed on calendar name (pyCalendar) and start date (pyStartDate) and holds data for daily business hours and scheduled holidays. Basic native Calendar concept in Pega7 is used in conjunction with Library Function/DateTime functions to calculate business days. Calendars are referenced on Data-Admin-Organization, Data-Admin-WorkBasket, and Data-Admin-Operator-ID instances as Calendar (pyCalendar). It is expected that calendar instances will be provided for each year and potentially multiple regions (locales).
pxDateTime (Date Picker Control) - it provides classic calendar-style popup UI for selecting dates.
pxCalendar (Outlook-style Day/Week/Month Calendar View) - pxCalendar is implemented under the PegaGadget-CalendarView class as a FINAL section provided in Pega7 by the Pega-Gadgets ruleset and available on the Case Manager portal.