Holidays in Colombia

Official national public holidays. Regional and religious observances may vary by area.

About Time in Colombia

For Nine Months, the National Clock Became an Energy Policy

On the night of 1 May 1992, time itself became part of the response to a national electricity shortage. Decree 717 moved legal time from five hours behind Coordinated Universal Time to four hours behind it. The wording was exact: the change took effect at 24:00 on 1 May, which is 00:00 on 2 May. A clock approaching midnight under UTC-5 therefore advanced directly into the new UTC-4 regime.

The measure came during a severe power crisis. Electricity rationing had already begun in March, and a Constitutional Court review later described an interconnected system unable to meet demand under exceptionally dry hydrological conditions, compounded by structural and operational weaknesses in the electricity sector. The decree presented the clock advance as a way to use more daylight and reduce electricity consumption. In everyday speech the experiment became known as Hora Gaviria.

This was not a normal recurring daylight-saving schedule. It was an emergency intervention with no annual rule behind it. Decree 267 of 5 February 1993 stated that rationing had fallen substantially and reservoir conditions had improved, then restored UTC-5 at 24:00 on 6 February. The transition was specified for 24:00 on 6 February, with clocks returning one hour to UTC-5.

The episode also exposes a problem that matters to historical timestamp conversion. Earlier releases of digital time-zone data encoded different dates for the 1992 and 1993 transitions. In IANA tz database release 2026d, the data encode the advance at 00:00 on 2 May 1992 and the return at 24:00 on 6 February 1993, matching the Colombian decrees. A timestamp from this short period can therefore be wrong by a full hour if software relies on outdated zone information.

The Four-Minute Correction Hidden in 1914

Before national time settled on an exact five-hour difference from Greenwich, Bogotá used a mean time tied to its longitude. The current IANA historical model gives Bogotá Mean Time as 4 hours, 56 minutes and 16 seconds behind Greenwich. When the zone changed to an even five hours behind Greenwich on 23 November 1914, clocks moved backward by 3 minutes and 44 seconds. It was a tiny correction compared with the one-hour jump of 1992, but it marked a much larger conceptual change: civil time no longer needed to reproduce the local solar longitude of the capital.

Contemporary international evidence also shows why minute-level precision should not be confused with minute-level uniformity. The geographer John Milne reported an offset of about 4 hours, 56 minutes and 16.4 seconds for Bogotá in 1899, yet he also noted that public clocks in the city could differ by as much as fifteen minutes. An astronomical mean time could be calculated very precisely while the clocks people actually saw in streets and buildings remained imperfectly synchronized.

There is an intriguing documentary coincidence on the date of the 1914 transition. A Colombian law dated 23 November approved the 1913 Paris convention for an international association intended to unify time by radiotelegraphic or other signals. The surviving legal text demonstrates participation in the international movement toward coordinated time signals, while the tz database places the switch from Bogotá Mean Time to the five-hour offset on that same date. The documents do not by themselves prove that the convention caused the domestic clock change, so the connection should not be stated more strongly than the evidence allows.

A Meridian Line Ran Through the Observatory Floor

Long before radio signals or atomic standards, precise time in Santafé de Bogotá was an astronomical problem. Construction of the Astronomical Observatory began in 1802 and the main building was completed in 1803. Francisco José de Caldas took charge of astronomical work there soon afterward. The building was designed not simply as a place to view the sky, but as an instrument in its own right.

One of its most important features was a meridian line laid across the floor. A small opening admitted sunlight so that the solar image could cross the line, forming a large gnomon arrangement. Meridian passage gave an observer a physical reference for local noon and for checking astronomical time. Caldas also criticized aspects of the original orientation and adapted the building to actual observational work near the equator.

The line later acquired an unusual history. Historical studies of the observatory record that the original lead meridian was removed during the upheaval of 1854 because troops needed the metal for bullets. The meridian was later restored in brass during the 1860s. A scientific reference line used to connect the motion of the Sun with measured time had literally been turned into ammunition.

Thirty-Seven Moons Do Not Fit a Gregorian Year

Another chronology developed on the Altiplano Cundiboyacense without reference to Greenwich at all. The best-known reconstruction of Muisca calendrical reckoning comes from material recorded by the priest José Domingo Duquesne in the late eighteenth century. His interpretation was later attacked as an invention, which makes modern discussion of the calendar a case where caution is more useful than repeating a neat diagram as settled fact.

Archaeoastronomical research by Manuel Arturo Izquierdo re-examined the Duquesne material and argued that it preserves genuine indigenous information. In that reconstruction, lunar counts are organized around multiples including 5, 20 and 37 moons. A 37-moon sequence functions as an important calendrical unit, while a larger cycle of 740 moons corresponds to about 59.8 solar years. These units do not map cleanly onto Gregorian years and should not be translated as if they were merely alternate names for twelve-month periods.

The evidence is valuable precisely because it shows a different problem of timekeeping. The task was not to assign a UTC offset to a clock but to reconcile observable lunar cycles, agricultural timing, ritual recurrence and long numerical sequences. Some details remain interpretive, so the safest historical description is that scholars have reconstructed a sophisticated lunar and lunisolar system from colonial accounts, linguistic evidence and archaeological material rather than recovered a complete pre-contact calendar manual.

That distinction also prevents a common mistake in writing about indigenous astronomy: a plausible reconstruction is not automatically a certainty. The Muisca material is strongest when treated as evidence for structured astronomical time reckoning, with the limits of the surviving record left visible.

UTC(INM) Is a Time Scale, Not Another Name for UTC-5

Modern legal time is much easier to state. Decree 2707 of 1982 formally adopted Coordinated Universal Time minus five hours for the whole republic and assigned responsibility for maintaining and providing legal time to the national metrology structure then operating within the Superintendence of Industry and Commerce. Today that function belongs to the Instituto Nacional de Metrología, which generates, monitors, coordinates and disseminates the official time signal.

The institute maintains a local realization called UTC(INM). This should not be confused with the civil offset. UTC-5 tells a clock user how local civil time relates to UTC. UTC(INM), by contrast, is a laboratory time scale generated from the national time and frequency standard and compared internationally. INM states that Colombia has contributed clock data to the realization of UTC since 2017, while the BIPM Circular T provides the regular comparison between UTC and participating local UTC(k) scales.

The physical basis is atomic rather than astronomical. INM documentation identifies cesium primary standards in its time and frequency work, and the legal-time service distributes the national signal through official web and NTP services. The path from a meridian line illuminated by the Sun to cesium oscillations and network synchronization is not just a story of increasing precision. It reflects a change in what a national clock is expected to do: provide a reproducible second, remain traceable to international time, and deliver the same timestamp to digital systems across an entire country.

Frequently Asked Questions