In Oracle Global Human Resources Cloud, a worker’s availability is determined by combining multiple data points that define their working and non-working time. When a work schedule is not assigned, the system relies on alternative sources to calculate availability, as seen in the "Check Availability" feature (e.g., in the Directory or My Team).

Option A: Contract Data defines employment terms (e.g., full-time/part-time status) but does not directly specify daily or hourly availability without a linked schedule or hours. It’s not a primary factor here.

Option B: Absences (e.g., vacation, sick leave) reduce a worker’s availability by indicating time they are not available to work. This is a key component, making it correct.

Option C: Calendar Events (e.g., public holidays, company-wide closures) from the worker’s assigned work day calendar affect availability by marking non-working days. This is included, making it correct.

Option D: Standard Working Hours, defined at the enterprise or legal employer level (via Manage Enterprise HCM Information or Manage Legal Entity HCM Information), provide a default working pattern (e.g., 9 AM–5 PM) when no specific work schedule is assigned. This is a fallback mechanism and is correct.

Option E: Time Sheet data tracks actual hours worked but is not used proactively to determine future availability; it’s more for payroll or historical analysis.

Thus, the three items used areB (Absences),C (Calendar Events), andD (Standard Working Hours), as outlined in "Using Global Human Resources" under Availability Management.