Missing time is a proposed phenomenon

Phenomenon

A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...

 reported by some people in connection with close encounter

Close encounter

In ufology, a close encounter is an event in which a person witnesses an unidentified flying object. This terminology and the system of classification behind it was started by astronomer and UFO researcher J. Allen Hynek, and was first suggested in his 1972 book The UFO Experience: A Scientific...

s with UFOs

Unidentified flying object

A term originally coined by the military, an unidentified flying object is an unusual apparent anomaly in the sky that is not readily identifiable to the observer as any known object...

 and abduction phenomena. The term missing time refers to a gap in conscious memory

Memory

In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

 relating to a specific period in time

Time

Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

. The gap can last from several minutes to several days in length. The memory of what happened during the missing time reported is often recovered through hypnosis

Hypnosis

Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...

 or during dream

Dream

Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not definitively understood, though they have been a topic of scientific speculation, philosophical intrigue and religious...

s.

Cases

One notable case is that of the Betty and Barney Hill abduction

Betty and Barney Hill abduction

Betty and Barney Hill were an American couple who claimed to have been abducted by extraterrestrials in a rural portion of New Hampshire on September 19–20, 1961....

. The Hills claim to have experienced a period of missing time after witnessing a UFO.

Controversy

Missing time is controversial in that apart from disbelief in UFO phenomenon, it is closely tied to other controversial issues such as recovered memories

Repressed memory

Repressed memory is a hypothetical concept used to describe a significant memory, usually of a traumatic nature, that has become unavailable for recall; also called motivated forgetting in which a subject blocks out painful or traumatic times in one's life...

 and hypnosis

Hypnosis

Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...

.

Possible causes

1. The subject is mistaken about the time, such as a departure time, so that an event seemed to take longer than it actually did.
2. The memory of the event, real or imagined, is traumatic so that the mind represses
   Repressed memory
   Repressed memory is a hypothetical concept used to describe a significant memory, usually of a traumatic nature, that has become unavailable for recall; also called motivated forgetting in which a subject blocks out painful or traumatic times in one's life...
   
    it. The concept and reality of repressed memories is debated among psychoanalysts and scientists, however, and many do not support the concept at all.
3. The event itself did not happen and the subject instead imagined as part of a hallucination
   Hallucination
   A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid,...
   
    caused by drugs
   Psychedelics, dissociatives and deliriants
   This general group of pharmacological agents can be divided into three broad categories: psychedelics, dissociatives, and deliriants. These classes of psychoactive drugs have in common that they can cause subjective changes in perception, thought, emotion and consciousness...
   
    or a seizure
   Seizure
   An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
   
    (Absence seizure
   Absence seizure
   Absence seizures are one of several kinds of seizures. These seizures are sometimes referred to as petit mal seizures ....
   
   ), or implanted during hypnosis.
4. Highway hypnosis
   Highway hypnosis
   Highway hypnosis, also popularly known as driving without attention mode or white line fever, is a mental state in which a person can drive a truck or automobile great distances, responding to external events in the expected manner with no recollection of having consciously done so...
   
   , or losing track of time while driving and having one's mind distracted.
5. The event is real, and the time was lost due to the Twin Paradox
   Twin paradox
   In physics, the twin paradox is a thought experiment in special relativity, in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth...
   
    predicted by Einstein's Special theory of relativity
   Special relativity
   Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
   
   : If the abductee was taken into the UFO which then flew into space at very high speeds, forming a loop trajectory eventually returning to Earth and letting the abductee free, time would be subject to relativistic effects. According to the special theory of relativity, while many hours or days have elapsed on Earth, the elapsed time experienced by the occupants of the craft will be much shorter if the UFO traveled at a sufficiently high velocity. Although the Twin Paradox itself is widely accepted as correct and true in physics, this explanation does not prove that UFO abductions themselves are real. It merely provides a plausible explanation for the missing time, should the abduction (or voluntary travel by a future man-made spacecraft) indeed occur. Furthermore, should an abduction have occurred, this would not explain the inability to remember the events which took place on board the hypothetical spacecraft, events which would, to the traveler, seem to pass in real time -- simply in less time than was "missing". Paranormal events such as UFO abductions are highly contested. See, for example, the evidence and skepticism for the five-day missing time in the well-known Travis Walton case.

Other occurrences

Missing time is often reported as a symptom of multiple personality disorder

Dissociative identity disorder

Dissociative identity disorder is a psychiatric diagnosis and describes a condition in which a person displays multiple distinct identities , each with its own pattern of perceiving and interacting with the environment....

.

A phenomenon similar to missing time can occur while listening to binaural beats

Binaural beats

Binaural beats or binaural tones are auditory processing artifacts, or apparent sounds, the perception of which arises in the brain for specific physical stimuli...

 designed to produce altered states of consciousness. In this context, it is common to the extent of being listed as a frequently asked question in the Monroe Institute

The Monroe Institute

The Monroe Institute is a nonprofit education and research organization devoted to the exploration of human consciousness, based in Faber, Virginia, United States. Upwards of 20,000 people are estimated to have attended TMI’s residential Gateway program during its first thirty years, with...

's Hemi-Sync

Hemi-Sync

Hemi-Sync is a trademarked brand name for a patented process used to create audio patterns containing binaural beats, which are commercialized in the form of audio CDs. Interstate Industries Inc., created by Hemi-Sync founder Robert Monroe, is the owner of the Hemi-Sync technology. Hemi-Sync is...

FAQ, where it is referred to as "clicking-out".