Glossary
What is Idle Time?
Short answer
Idle time is the period during which a computer's keyboard and mouse receive no input. On macOS, the system reports idle time via the HID (Human Interface Device) event subsystem.
Full definition
In productivity, idle time specifically refers to stretches when a user has stopped interacting with their machine — no typing, no cursor movement, no scrolling. macOS exposes this via `CGEventSourceSecondsSinceLastEventType` and related APIs. Idle time differs from 'away time' (which often requires camera-based detection) and from 'app time' (which measures foreground window, not human attention).
The average knowledge worker's computer sits idle for 28% of the 'working' day (Source: RescueTime 2023 report).
Examples
- IdleMac triggers a voice alert when idle time crosses your threshold.
- Screensavers activate based on idle time.
- Time trackers like Timing auto-pause billing when idle time exceeds a limit.