The DOMHighResTimeStamp type is a double and is used to store a time value. The value could be a discrete point in time or the difference in time between two discrete points in time. The unit is milliseconds and should be accurate to 5 µs (microseconds). However, if the browser is unable to provide a time value accurate to 5 microseconds (due, for example, to hardware or software constraints), the browser can represent the value as a time in milliseconds accurate to a millisecond.