A spa day falls apart when calendars don't reflect reality. Inntelligent schedules by specialist skills, treatment room and wet-area rules, so a couples massage in the double suite can be locked to both therapists and one room, with cleanup buffers and heat-bed reset time added automatically. Beauty salons get processing blocks for colour work (e.g., 30′ apply + 40′ develop + 20′ finish), while hydro/thermal journeys can be booked as timed entries to avoid overcrowding in sauna/steam. Spa reception sees a single live picture: online deposits, contraindication notes (e.g., pregnancy massage), and auto-warnings if a guest tries to book hammam and deep tissue back-to-back without a recovery buffer. Pool guests can scan a QR at the pool bar to reserve a late check-out thermal slot - the calendar updates everywhere instantly.