Abstract: This disclosure is directed to a system including alarming functionality with contextual reactivity. Alarming functionality may be implemented in an alarm system to determine when to generate an alarm. A user may activate the alarming functionality without specifying an alarm time. The alarming functionality may then utilize context information to propose an alarm time. The user may then approve the alarm time. In the duration of time that follows, the alarming functionality may cause the context information to be updated. The alarming functionality may determine if the alarm time should be updated based on the updated context information, and may proceed to adjust the alarm time accordingly. An alarm may then be generated at the alarm time. The alarming functionality may further receive sensor information, and may use the sensor information to determine, for example, whether to regenerate the alarm or deactivate the alarm.