The timestamp read-only property of the Notification interface returns a DOMTimeStamp, as specified in the timestamp option of the Notification() constructor.

API Notifications Property Reference timeStamp

Returns the time (in milliseconds) at which the event was created.

API DOM Event Gecko Property Reference timeStamp

The timestamp read-only property of the VRPose interface returns the current time stamp of the system — a monotonically increasing value representing the time since the current app was started.

API Experimental Expérimental Property Reference Référence timeStamp Virtual Reality VR VRPose WebVR