The Unreality of Time

"The Unreality of Time" is the best-known philosophical work of the Cambridge idealist J. M. E. McTaggart (1866–1925). In the argument, first published as a journal article in Mind in 1908, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient. A slightly different version of the argument appeared in 1927 as one of the chapters in the second volume of McTaggart's greatest work, The Nature of Existence.[1]

The argument for the unreality of time is popularly treated as a stand-alone argument that does not depend on any significant metaphysical principles (e.g. as argued by C. D. Broad 1933 and L. O. Mink 1960). R. D. Ingthorsson disputes this, and argues that the argument can only be understood as an attempt to draw out certain consequences of the metaphysical system that McTaggart presents in the 1st Volume of The Nature of Existence (Ingthorsson 1998 & 2016).

It is helpful to consider the argument as consisting of three parts. In the first part, McTaggart offers a phenomenological analysis of the appearance of time, in terms of the now famous A- and B-series (see below for detail). In the second part, he argues that a conception of time as only forming a B-series but not an A-series is an inadequate conception of time because the B-series does not contain any notion of change. The A-series, on the other hand, appears to contain change and is thus more likely to be an adequate conception of time. In the third and final part, he argues that the conception of time forming an A-series is contradictory and thus nothing can be like an A-series. Since the A- and the B- series exhaust possible conceptions of how reality can be temporal, and neither is adequate, the conclusion McTaggart reaches is that reality is not temporal at all.

The phenomenological analysis: the A- and B-series

To frame his argument, McTaggart initially offers a phenomenological analysis of how time appears to us in experience. Time appears, he says, in the form of events standing in temporal positions, of which there are two kinds. On the one hand events are earlier than and later than each other, and on the other hand they are future, present, and past, and continually changing their position in terms of futurity, presentness, and pastness. The two kinds of temporal positions each represent events in time as standing in a certain order which McTaggart chooses to call the A-series and the B-series. The A-series represents the series of positions determined as future, present, and past, and which continuously pass from the distant future towards the present, and through the present into the remote past. The B-series represents the series of positions determined as earlier than or later than each other. The determinations of the B-series hold between the events in time, and never change. If an event ever is earlier or later than some other event, then their respective position in time never changes. The determinations of the A-series must hold to something outside of time, something that does not itself change its position in time, but in relation to which the events in time pass from being future, present, and past. Surprisingly, McTaggart does not suggest the present, or NOW, as this something whose position in time is fixed and unchanging. He just says that it will be difficult to identify any such entity (seeing as it is outside time). Broad explains that McTaggart believed that the difficulty of identifying this entity was serious enough in its own right to be persuaded that time is unreal, but thinks that the contradiction of the A-series is still more convincing, wherefore he leaves this particular difficulty aside.[2]

The atemporality of the B-series

McTaggart argues that the conception of time as only forming a B-series is inadequate because the B-series does not change, and change is of the essence of time. If any conception of reality represents it as changeless, then this is a conception of an atemporal reality. The B-series does not change because earlier-later relationships never change (e.g. the year 2010 is always later than 2000). The events that form a B-series must therefore also form an A-series in order to count as being in time, i.e. they must pass from future to present, and from present to past, in order to change.

The A- and B-series are not mutually exclusive. If events form an A-series they automatically also form a B-series (anything in the present is earlier than anything in the future, and later than everything past). The question is not therefore whether time forms an A- or a B-series; the question is whether time forms both an A- and a B-series, or only a B-series.

The proponents of the B-view of time typically respond by arguing that even if events do not change their positions in the B-series, it does not follow that there can be no change in the B-series. This conclusion only follows if it is assumed that events are the only entities that can change. There can be change in the B-series in the form of objects bearing different properties at different times (Braithwaite 1928; Gotshalk 1930; Marhenke 1935; Smart 1949; Mellor 1981 & 98; Oaklander 1984; LePoidevin 1991; Dyke 2002).[3]

The suggestion that the B-view of time can escape the problem by appealing to particulars that endure through time and have different properties at different times is controversial in its own right, but it is generally assumed that this is a controversy that has nothing to do with McTaggart. Instead it is treated as a separate issue, the question of whether things can endure in B-time. However, as Ingthorsson has argued, McTaggart does discuss variation in the properties of persistent entities in the 1st Volume of The Nature of Existence, and there comes to the conclusion that variation in the properties of things between times is not change but mere variation between the temporal parts of things (Ingthorsson 2001).

The contradiction of the A-series

Attacking the A-series, McTaggart argues that any event in the A-series is past, present, and future, which is contradictory in that each of those properties excludes the other two. McTaggart admits that the contradictory nature of the A-series may not be obvious, because it would appear that events never are simultaneously future, present, and past, but only successively so. However, there is a contradiction, he insists, because any attempt to explain why they are future, present, and past, at different times is (i) circular because we would need to describe the successive order of those "different times" again by invoking the determinations of being future, present or past, and (ii) this in turn will inevitably lead to a vicious infinite regress. The vicious infinite regress arises, because to explain why the second appeal to future, present, and past, doesn't lead again to the same difficulty all over, we need to explain that they in turn apply successively and thus we must again explain that succession by appeal to future, present, and past, and there is no end to such an explanation. It is the validity of the argument in favour of a vicious infinite regress that has received the most attention in 20th Century philosophy of time.

In the later version of the argument, in The Nature of Existence,[4] McTaggart no longer advances the circularity objection. This is, arguably, because by then he has come to treat tense as a simple and indefinable notion, and thus cannot contend that the terms need to be explained at all in order to be applied. He now instead argues that even if it is admitted that they are simple and indefinable, and thus can be applied without further analysis, they still lead to contradiction.

Philosophers who favour the B-view of time tend to find McTaggart's argument against the A-series to demonstrate conclusively that tense involves a contradiction.[5] On the other hand, philosophers who favour the A-view of time struggle to see why the argument should be considered to have any force. Two of the most commonly invoked objections are, first, that McTaggart is mistaken about the phenomenology of time; that he is claiming to see a contradiction in the appearance of time, where none is apparent.[6] Second, that McTaggart is mistaken about the semantics of tensed discourse. The idea here is that claims like "M is present, has been future, and will be past" can only imply a contradiction if it is interpreted as saying that M is all at once future in the past, present in the present, and also past in the future. This reading, it is argued, is absurd because "has been" and "will be" indicate that we are not talking about how M currently is, but instead of how M once was, but is no longer, and how it will be, but is not yet. Hence it is wrong to think of the expression as an attribution to M of futurity, presentness, and pastness, all at once (Marhenke 1935; Broad 1938; Mink 1960; Prior 1967; Christensen 1974; Lloyd 1977; Lowe 1987).

Ingthorsson has argued that the reason for this incommensurability between the proponents of the A- and B-views is found in the prevailing view that McTaggart's argument is a stand-alone argument. If it is read in that way, the proponents of each view will understand the argument against the background of their respective views of time, and come to incompatible conclusions (1998 & 2016). Indeed, on closer scrutiny it will be found that McTaggart explicitly claims that in "The Unreality of Time" he is inquiring whether reality can have the characteristics it appears to have in experience (notably being temporal and material) given his earlier conclusions about what reality must really be like in Absolute Reality. In the introduction to the 2nd Volume of The Nature of Existence, he says:

Starting from our conclusions as to the general nature of the existent, as reached in the earlier Books, we shall have to ask, firstly which of these characteristics can really be possessed by what is existent, and which of them, in spite of the primâ facie appearance to the contrary, cannot be possessed by anything existent (1927: sect. 295).

And he continues:

It will be possible to show that, having regard to the general nature of the existent as previously determined, certain characteristics, that we consider here for the first time, cannot be true of the existent (1927: sect. 298).

As Ingthorsson notes, the most central result of McTaggart's earlier inquiry into the general nature of the existent in Absolute Reality, an inquiry McTaggart claims is based entirely on a priori arguments (i.e. such as do not rely on any empirical observations), is that existence and reality coincide and have no degrees: either something exists and thus is real, or it does not. It immediately follows that for the future and past to be real, they must exist. This is why he interprets the statement "M is present, has been future, and will be past" as a statement about M existing in the present bearing the property of being present, and existing in the past bearing the property of being future, and existing in the future bearing the property of being past. This interpretation of the expression, if correct, does say that M is future, present, and past, which is contradictory. However, since it starts from the premise that the future and past can only be real by existing, then it remains to show that this is what the A-view of time assumes.

The C-series

Having come to the conclusion that reality can neither form an A- nor a B-series, despite appearances to the contrary, then McTaggart finds it necessary to explain what the world is really like such that it appears to be different from what it appears to be. Here is where the C-series comes into play. McTaggart does not say much about the C-series in the original journal article, but in The Nature of Existence he devotes six whole chapters to discuss it (1927: Chs. 44–9).

The C-series is rarely given much attention. When it is mentioned, it is described as "an expression synonymous with 'B-series' when the latter is shorn of its temporal connotations" (Shorter 1986: 226). There is a grain of truth in this, but there is more to the C-series than this. Stripping the temporal features from the B-series only gives what the C- and B-series have minimally in common, notably the constituents of the series and the formal characteristics of being linear, asymmetric, and transitive. However, the C-series has features that the B-series does not have. The constituents of the C-series are mental states (a consequence of McTaggart's argument in Ch. 34 of The Nature of Existence that reality cannot really be material), which are related to each other on the basis of their conceptual content in terms of being included in and inclusive of (1927: sect. 566 & Ch. 60). These atemporal relations are meant to provide what the earlier/later than relation cannot, notably explain why an illusion of change and temporal succession can arise in an atemporal reality.

Influence of "The Unreality of Time"

McTaggart's argument has had an enormous influence on the philosophy of time. His phenomenological analysis of the appearance of time has been accepted as good and true even by those who firmly deny the end conclusion that time is unreal. For instance, J. S. Findlay (1940) and A. Prior (1967) took McTaggart's phenomenological analysis as their point of departure in the development of modern tense logic.

McTaggart's characterisation of the appearance of time in terms of the A- and B-series served to sharpen the contrast between the two emerging and rival views of time that we now know as the A- and B-views of time. The assumption is that the A-view, in accepting the reality of tense, represent time as being like an A-series, and that the B-view, in rejecting the reality of tense, represent time as being like a B-series.

The two objections that McTaggart develops against the conception of time as forming an A- and a B-series are still the two main objections with which the A- and B-views of time struggle. Is the A-view contradictory, and is the B-view able to incorporate an account of change.

The controversy about McTaggart's argument for the unreality of time continues unabated (see, for instance, Smith 2011; Cameron 2015; Mozersky 2015; Ingthorsson 2016).


See also


  1. ^ J. M. E. McTaggart, "The Unreality of Time", Mind 17: 457–73; reprinted in J. M. E. McTaggart, The Nature of Existence, Vol. 2, 1927, Cambridge: Cambridge University Press: Book 5, Chapter 33.
  2. ^ Broad 1938: p. 317-8
  3. ^ e.g. as argued by: Braithwaite 1928; Gotshalk 1930; Marhenke 1935; Smart 1949; Mellor 1981 & 98; Oaklander 1984; LePoidevin 1991; Dyke 2002
  4. ^ McTaggart 1927: ch. 33
  5. ^ For instance: Dummett 1960; Mellor 1981 & 1998; Oaklander 1984; LePoidevin 1992
  6. ^ Gotschalk 1930; Broad 1938: 313; Oakley 1946-7; Prior 1967: 5–6; Christensen 1974; Baldwin 1999.


  • Baldwin, Thomas. 1999. "Back to the Present", Philosophy 74(288): 177–97.
  • Braithwaite, R. B. 1928. "Symposium: Time and Change", Proceedings of the Aristotelian Society, Supplementary Volumes, 8, Mind Matter and Purpose: 143–188.
  • Broad, C.D. 1933. An Examination of McTaggart's Philosophy, Vol. I. Cambridge: Cambridge University Press.
  • Broad, C. D. 1938. Examination of McTaggart's Philosophy, Vol. II. Cambridge: Cambridge University Press.
  • Cameron, Ross. 2015. The Moving Spotlight: An Essay On Time and Ontology. Oxford: Oxford University Press.
  • Christensen, Ferrel. 1974. "McTaggart"s Paradox and the Nature of Time", Philosophical Quarterly 24: 289–99.
  • Dummett, Michael. 1960. "A Defense of McTaggart"s Proof of the Unreality of Time", Philosophical Review 69: 497–504.
  • Dyke, Heather. 2002. "McTaggart and the Truth about Time", Royal Institute of Philosophy Supplement 50, Supplement: 137–52.
  • Findlay, J. N. 1941. "Time: A Treatment of some Puzzles", Australasian Journal of Philosophy 19 (3): 216–35.
  • Gotshalk, D. W. 1930, "McTaggart on Time", Mind 39(153): 26–42.
  • Ingthorsson, R. D. 1998. "McTaggart and the Unreality of Time", Axiomathes 9(3): 287–306.
  • Ingthorsson, R. D. 2001. "Temporal Parity and the Problem of Change", SATS–Nordic Journal of Philosophy 2(2): 60–79.
  • Ingthorsson, R. D. 2016. McTaggart's Paradox. New York: Routledge.
  • LePoidevin, Robin. 1991. Change, Cause and Contradiction: A Defence of the Tenseless Theory of Time. London: Macmillan Press Ltd.
  • Lloyd, Genevieve. 1977. "Tense and Predication", Mind 86: 433–8.
  • Lowe, E. J. 1987. "The Indexical Fallacy in McTaggart"s Proof of the Unreality of Time", Mind 96: 62–70.
  • Marhenke, P. 1935. "McTaggart"s Analysis of Time". In The Problem of Time, edited by Stephen C. Pepper et al. University of California Publications in Philosophy, Vol 18 (6). Berkeley, CA: University of California Publications; repr. 1969 New York: Johnson Reprint Corp: 151–74.
  • Mellor, D. H. 1981. Real Time. Cambridge University Press, Cambridge.
  • Mellor, D. H. 1998. Real Time II. Routledge, London.
  • Mozersky, Joshua M. 2015. Time, Language, and Ontology. Oxford: Oxford University Press.
  • Oakeley, Hilda D. 1946–7. "The Philosophy of Time and the Timeless in McTaggart's Nature of Existence", Proceedings of the Aristotelian Society 47: 105–28.
  • Oaklander, L. Nathan. 1984. Temporal Relations and Temporal Becoming: A Defense of a Russellian Theory of Time. Lanham: University Press of America.
  • Prior, Arthur N. 1967. Past Present and Future. Oxford: Clarendon Press.
  • Shorter, Michael. 1986. "Subjective and Objective Time", Proceedings of the Aristotelian Society, Supplementary Volumes 60: 223–34.
  • Smart, J. J. C. 1949. "The River of Time", Mind 58(232): 483–94.
  • Smith, Nicholas J. J. 2011. "Inconsistency in the A–Theory", Philosophical Studies 156: 231–47.

Further reading

  • Peter Bieri, 1972. Zeit und Zeiterfahrung (Frankfurt am Main: Suhrkamp)
  • C. D. Broad, An examination of McTaggart's philosophy. Vol. 1. Cambridge University Press, 1933
  • C. D. Broad, An examination of McTaggart's philosophy. Vol. 2. Cambridge University Press, 1938
  • Gerald Rochelle, 1991. The Life and Philosophy of J.McT.E. McTaggart 1866-1925 (Lewiston NY: Edwin Mellen Press)
  • Gerald Rochelle, 1998. Behind Time: The incoherence of time and McTaggart's atemporal replacement (Aldershot, Ashgate)
  • Gerald Rochelle, 1998, "Killing time without injuring eternity — McTaggart's C series," Idealistic Studies 28(3): 159-69.
  • Robin Le Poidevin ed., 2002, "Questions of Time and Tense" (Oxford: Oxford University Press)
  • R. D. Ingthorsson, 2016, McTaggart's Paradox (New York: Routledge).

External links

A series and B series

In philosophy, A series and B series are two different descriptions of the temporal ordering relation among events. The two series differ principally in their use of tense to describe the temporal relation between events. The terms were introduced by the Scottish idealist philosopher John McTaggart in 1908 as part of his argument for the unreality of time, but since then they have become widely used terms of reference in modern discussions of the philosophy of time.


An astrarium, also called a planetarium, is the mechanical representation of the cyclic nature of astronomical objects in one timepiece. It is an astronomical clock.

B-theory of time

The B-theory of time is the name given to one of two positions regarding philosophy of time. B-theorists argue that the flow of time is an illusion, that the past, present and future are equally real, and that time is tenseless. This would mean that temporal becoming is not an objective feature of reality.

B-theory is often drawn upon in theoretical physics, and in theories such as eternalism.


Chronometry (from Greek χρόνος chronos, "time" and μέτρον metron, "measure") is the science of the measurement of time, or timekeeping. Chronometry applies to electronic devices, while horology refers to mechanical devices.

It should not to be confused with chronology, the science of locating events in time, which often relies upon it.

Common year

A common year is a calendar year with 365 days, as distinguished from a leap year, which has 366. More generally, a common year is one without intercalation. The Gregorian calendar, (like the earlier Julian calendar), employs both common years and leap years to keep the calendar aligned with the tropical year, which does not contain an exact number of days.

The common year of 365 days has 52 weeks and one day, hence a common year always begins and ends on the same day of the week (for example, January 1 and December 31 fell on a Sunday in 2017) and the year following a common year will start on the subsequent day of the week. In common years, February has four weeks, so March will begin on the same day of the week. November will also begin on this day.

In the Gregorian calendar, 303 of every 400 years are common years. By comparison, in the Julian calendar, 300 out of every 400 years are common years, and in the Revised Julian calendar (used by Greece) 682 out of every 900 years are common years.


Endurantism or endurance theory is a philosophical theory of persistence and identity. According to the endurantist view, material objects are persisting three-dimensional individuals wholly present at every moment of their existence, which goes with an A-theory of time. This conception of an individual as always present is opposed to perdurantism or four dimensionalism, which maintains that an object is a series of temporal parts or stages, requiring a B-theory of time. The use of "endure" and "perdure" to distinguish two ways in which an object can be thought to persist can be traced to David Lewis.

Eternalism (philosophy of time)

Eternalism is a philosophical approach to the ontological nature of time, which takes the view that all existence in time is equally real, as opposed to presentism or the growing block universe theory of time, in which at least the future is not the same as any other time. Some forms of eternalism give time a similar ontology to that of space, as a dimension, with different times being as real as different places, and future events are "already there" in the same sense other places are already there, and that there is no objective flow of time. It is sometimes referred to as the "block time" or "block universe" theory due to its description of space-time as an unchanging four-dimensional "block", as opposed to the view of the world as a three-dimensional space modulated by the passage of time.


Eternity in common parlance is an infinitely long period of time. In classical philosophy, however, eternity is defined as what exists outside time while sempiternity is the concept that corresponds to the colloquial definition of eternity.

Eternity is an important concept in many religions, where the god or gods are said to endure eternally. Some, such as Aristotle, would say the same about the natural cosmos in regard to both past and future eternal duration, and like the eternal Platonic forms, immutability was considered essential.

Event (philosophy)

In philosophy, events are objects in time or instantiations of properties in objects.


HD2IOA is the callsign of a time signal radio station operated by the Navy of Ecuador. The station is located at Guayaquil, Ecuador and transmits in the HF band on 3.81 and 7.6 MHz.The transmission is in AM mode with only the lower sideband (part of the time H3E and the rest H2B/H2D) and consists of 780 Hz tone pulses repeated every ten seconds and voice announcements in Spanish.

While sometimes this station is described as defunct, reception reports of this station on 3.81 MHz appear regularly at the Utility DX Forum.

Intercalation (timekeeping)

Intercalation or embolism in timekeeping is the insertion of a leap day, week, or month into some calendar years to make the calendar follow the seasons or moon phases. Lunisolar calendars may require intercalations of both days and months.

J. M. E. McTaggart

John McTaggart Ellis McTaggart, FBA (; 3 September 1866 – 18 January 1925), was an idealist metaphysician. For most of his life McTaggart was a fellow and lecturer in philosophy at Trinity College, Cambridge. He was an exponent of the philosophy of Georg Wilhelm Friedrich Hegel and among the most notable of the British idealists. McTaggart is known for "The Unreality of Time" (1908), in which he argues that time is unreal. The work has been widely discussed through the 20th Century and into the 21st.


The minute is a unit of time or angle. As a unit of time, the minute is most of times equal to ​1⁄60 (the first sexagesimal fraction) of an hour, or 60 seconds. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds (there is a provision to insert a negative leap second, which would result in a 59-second minute, but this has never happened in more than 40 years under this system). As a unit of angle, the minute of arc is equal to ​1⁄60 of a degree, or 60 seconds (of arc). Although not an SI unit for either time or angle, the minute is accepted for use with SI units for both. The SI symbols for minute or minutes are min for time measurement, and the prime symbol after a number, e.g. 5′, for angle measurement. The prime is also sometimes used informally to denote minutes of time.


Perdurantism or perdurance theory is a philosophical theory of persistence and identity. The perdurantist view is that an individual has distinct temporal parts throughout its existence. Perdurantism is usually presented as the antipode to endurantism, the view that an individual is wholly present at every moment of its existence.The use of "endure" and "perdure" to distinguish two ways in which an object can be thought to persist can be traced to David Kellogg Lewis (1986). However, contemporary debate has demonstrated the difficulties in defining perdurantism (and also endurantism). For instance, the work of Ted Sider (2001) has suggested that even enduring objects can have temporal parts, and it is more accurate to define perdurantism as being the claim that objects have a temporal part at every instant that they exist. Currently there is no universally acknowledged definition of perdurantism. Others argue that this problem is avoided by creating time as a continuous function, rather than a discrete one.

Perdurantism is also referred to as "four-dimensionalism" (by Ted Sider, in particular) but perdurantism also applies if one believes there are temporal but non-spatial abstract entities (like immaterial souls or universals of the sort accepted by David Malet Armstrong).

Philosophical presentism

Philosophical presentism is the view that neither the future nor the past exist. In some versions of presentism, this view is extended to timeless objects or ideas (such as numbers). According to presentism, events and entities that are wholly past or wholly future do not exist at all. Presentism contrasts with eternalism and the growing block theory of time which hold that past events, like the Battle of Waterloo, and past entities, like Alexander the Great's warhorse Bucephalus, really do exist, although not in the present. Eternalism extends to future events as well.

Static interpretation of time

The static interpretation of time is a view of time which arose in the early years of the 20th century from Einstein's special relativity and Hermann Minkowski's extension of special relativity in which time and space were famously united in physicists' thinking as spacetime.

Essentially the universe is regarded as akin to a reel of film – which is a wholly static physical object – but which when played through a movie projector conjures a world of movement, color, light and change. In the static view our whole universe – our past, present, and future are fixed parts of that reel of film, and the projector is our consciousness. But the 'happenings' of our consciousness have no objective significance – the objective universe does not happen, it simply exists in its entirety, albeit perceived from within as a world of changes.

The alternative, and commonly assumed view, is that the world unfolds in existence, that our present has some wider physical significance, because the universe evolves in step with it.

The static view is the simpler in that all that is held to exist is the physical ordering of the universe. All that there is at every time simply exists. The unfolding view requires an additional quality to the universe – that besides the physical ordering there is some quality of coming into and out of existence.

One can argue that the onus is therefore upon those who propose it, that the world unfolds, and that this additional quality they hold to (absent from special relativity) is indeed a physical feature of the world. There is however as yet no proof, experiment, or measurement, to show that our conscious experience of an unfolding present has any objective physical significance, or that the universe is anything other than static.

The static view is however commonly rejected for psychological, not scientific reasons, because it leads to a fatalistic or "fixed" conclusion about human existence – our 'past', 'present', and 'future' being what they are – there is no contingency in the world and no possibility of 'altering' or creating the future through some act of will – the future exists. It is simply that our consciousness has not yet reached it.


In philosophy, temporality is traditionally the linear progression of past, present, and future. However, some modern-century philosophers have interpreted temporality in ways other than this linear manner. Examples would be McTaggart's The Unreality of Time, Husserl's analysis of internal time consciousness, Martin Heidegger's Being and Time (1927), George Herbert Mead's Philosophy of the Present (1932), and Jacques Derrida's criticisms of Husserl's analysis, as well as Nietzsche's eternal return of the same, though this latter pertains more to historicity, to which temporality gives rise.

In social sciences, temporality is also studied with respect to human's perception of time and the social organization of time. The perception of time undergoes significant change in the three hundred years between the Middle Ages and Modernity.

Tomorrow (time)

Tomorrow is a temporal construct of the relative future; literally of the day after the current day (today), or figuratively of future periods or times. Tomorrow is usually considered just beyond the present and counter to yesterday. It is important in time perception because it is the first direction the arrow of time takes humans on Earth.


YVTO is the callsign of the official time signal from the Juan Manuel Cagigal Naval Observatory in Caracas, Venezuela. The content of YVTO's signal, which is a continuous 1 kW amplitude modulated carrier wave at 5.000 MHz, is much simpler than that broadcast by some of the other time signal stations around the world, such as WWV.

The methods of time transmission from YVTO are very limited. The broadcast employs no form of digital time code. The time of day is given in Venezuelan Standard Time (VET), and is only sent using Spanish language voice announcements. YVTO also transmits 100 ms-long beeps of 1000 Hz every second, except for thirty seconds past the minute. The top of the minute is marked by a 0.5 second 800 Hz tone.The station previously broadcast on 6,100 MHz but appears to have changed to the current frequency by 1990.

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