Holidays in Costa Rica

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

About Time in Costa Rica

Sixteen Seconds Destroyed Cartago in 1910

At 6:50 p.m. on 4 May 1910, a powerful local earthquake struck Cartago. The Red Sismológica Nacional identifies it as one of the most destructive earthquakes in Costa Rican history and gives its magnitude as 6.4 Ms. The shaking was brief. Instruments at the Observatorio Nacional recorded a duration of only sixteen seconds.

Those seconds were enough to devastate a city already weakened by another damaging earthquake on 13 April. Buildings collapsed across Cartago, many people had almost no time to escape, and the death toll is commonly estimated at around 700. Thousands were injured, with many survivors transported by train to hospitals in San José.

The disaster occurred during an extraordinary period of public anxiety. Halley's Comet was approaching its highly anticipated 1910 passage, and Costa Rican newspapers were filled with astronomical reports, predictions and speculation. Historian Ronald Díaz Bolaños documents how astronomy had become a major public subject by then, while contemporary press coverage sometimes mixed scientific information with alarming claims. The April earthquakes intensified fears among people who believed that the comet, earthquakes and volcanic activity might somehow be connected.

The sequence shows an important divide between measured and imagined time. The observatory could record an earthquake lasting sixteen seconds, newspapers could publish predicted dates for Halley's passage, and scientists could discuss celestial mechanics. At the same time, the closeness of several frightening events in the calendar encouraged causal connections that modern science does not support. In 1910, precise timing became part of both scientific evidence and public fear.

Arenal Stayed in Eruption for More Than Forty-Two Years

On the morning of 29 July 1968, Arenal began the eruptive period that would define the volcano for an entire generation. The Red Sismológica Nacional describes the opening event as a major explosion accompanied by pyroclastic currents that devastated Pueblo Nuevo and Tabacón and caused 78 deaths.

The eruption did not end after the initial catastrophe. Arenal entered a prolonged state of explosive and effusive activity, producing lava flows, incandescent blocks, ash emissions and occasional pyroclastic flows. Smithsonian's Global Volcanism Program dates the continuous eruptive period from 29 July 1968 until approximately December 2010.

That span exceeds forty-two years. Someone born during the opening explosions could have reached middle age while the same eruptive episode was still continuing. The volcano's behavior changed repeatedly during that period. The RSN identified major phases of stronger activity in June 1975, from May to August 1984, and again in February and March 1987, while lower-level explosions and lava extrusion continued between the larger episodes.

The ending was much less dramatic than the beginning. In May 2010, incandescent flows were still descending the western flank and Arenal National Park was temporarily closed. By September activity had declined sharply. A few sporadic Strombolian explosions were reported in December, after which sustained explosive activity ceased. Smithsonian therefore places the end of the eruptive period in December 2010 rather than on one spectacular final eruption date.

This makes Arenal an unusual chronological record. The important unit is not merely the minute of an explosion or the date of an evacuation, but a continuous volcanic episode measured across more than four decades.

The News of Independence Needed Almost a Month to Reach Costa Rica

Central American independence was declared in Guatemala City on 15 September 1821, the date now commemorated nationally in Costa Rica. But people in Costa Rica did not learn of that decision instantly. There was no telegraph, railway or electronic communication linking the province with Guatemala.

The Ministry of Culture and the National Archive reconstruct the information journey in detail. Documents carrying news of the decisions made in Guatemala and León travelled south by courier. On 13 October, twenty-eight days after the Guatemala declaration, the mounted mail reached San José and continued to Cartago, arriving there around noon.

The delay meant that historical events now grouped under a single Independence Day actually unfolded over weeks. Once the documents arrived, municipalities debated what position to take. Additional communications from Nicaragua followed. On 29 October an extraordinary open council met in Cartago and signed the act declaring independence from the Spanish government under the political arrangement then being discussed with the Mexican Empire.

The calendar continued to structure the process after the signature. The Cartago act called for independence to be publicly proclaimed and sworn on Thursday, 1 November. Archival research records plans for three evenings of illumination and music from 6 to 9 p.m., together with artillery salutes and a bullfight on the day of the proclamation.

Modern commemorations compress this sequence into 15 September, but the historical communication network produced a very different experience. A political decision made hundreds of kilometers away required four weeks to become actionable information in Costa Rica. The delay between event, message and local response was part of the political reality itself.

At the First National Observatory, Weather Had to Be Measured on Schedule

Scientific timekeeping became institutionalized in Costa Rica during the late nineteenth century. The government created the Instituto Meteorológico Nacional on 7 April 1888, with Swiss scientist Henri Pittier as director. It developed from the observatory established in San José the previous year and later became part of the Instituto Físico-Geográfico Nacional.

The early observatory depended on observations taken repeatedly at defined hours. Records from 1888 organize San José temperature measurements around 7 in the morning, 2 in the afternoon and 9 at night. A meteorological observation made at an unspecified moment was much less useful for comparison, because temperature, pressure and humidity change during the day. Regular observation times converted individual measurements into a series that could be compared from one day to the next.

The information then had to move physically. Historical research on the institution records the recollections of José Fidel Tristán, who as a student collected Pittier's observations after classes and carried them to the Imprenta Nacional. They appeared in La Gaceta the following day. A scientific observation therefore passed through a daily chain: measurement, transcription, hand delivery, typesetting and publication.

The network soon extended beyond San José. Stations collected rainfall and other meteorological information in different regions, including the Caribbean. Costa Rica had already participated in an international meteorological data network in 1877, and the institution created in 1888 provided a permanent national structure for producing comparable observations.

This was a different kind of clock discipline from railway timetables or office hours. Repeating a measurement at the same time each day made chronology part of the scientific method. Without that repetition, a long climate record would contain numbers but lose much of its comparability.

The Railway Reduced San José to Limón From About a Week to Six Hours

The completion of the Atlantic railway in 1890 changed the practical meaning of distance inside Costa Rica. Historical research from the Universidad Nacional estimates that the journey between the Central Valley and the Caribbean, which could previously occupy about a week, was reduced to roughly six hours by rail.

Once the line was operating, minutes on a timetable became economically important. Passenger departures were published in newspapers and posted at stations. In February 1899, for example, the Costa Rica Railway announced a new timetable effective from 1 March and specifically warned passengers that trains from both San José and Limón would depart at 8:45 a.m.

The railway also imposed smaller divisions of the day on urban transport. A 1905 timetable for the San José tramway scheduled service every thirty minutes from 5:30 a.m. until 2 p.m., then every hour until 10 p.m. Moving around the capital increasingly meant arranging activity around published departure intervals rather than simply leaving when conditions seemed convenient.

Rail schedules could themselves become formal legal and operational documents. A surviving 1931 timetable for the Pacific Railway states that it entered into force at 0:01 on 11 May and cancelled the preceding timetable. The schedule did not merely describe when trains usually ran. From one specified minute onward, it replaced an older operating order.

The railway therefore changed time in two senses. It compressed journeys that had been measured in days into journeys measured in hours, and it encouraged institutions and passengers to treat specific clock times as commitments that had to be coordinated across stations.

In 2026 Costa Rica Gave Its Official Time a New Legal and Atomic Foundation

Costa Rica made a major change to the institutional definition of national time in 2026 without asking anyone to move a clock. Executive Decree 45790-MEIC established a modern framework for the Hora Oficial de Costa Rica and aligned the national reference with the country's current metrology system and international standards.

The decree assigns responsibility for determining and maintaining official time through the national measurement infrastructure. LACOMET identifies the ICE-LAMETRO Time and Frequency Laboratory as the designated laboratory responsible for this function. Its standards are based on an ensemble of high-accuracy atomic clocks rather than on a single public clock or astronomical observation.

The change is important because modern official time has to serve systems that cannot tolerate arbitrary disagreement between clocks. Telecommunications, power networks, digital certificates, financial transactions, computer logs, laboratory measurements and other technical systems depend on synchronized timestamps. A clock can appear correct to a human while still being unsuitable as a traceable technical reference.

The laboratory's capabilities extend beyond displaying the hour. LACOMET lists internationally recognized calibration capabilities in time intervals from 86,400 to 604,800 seconds and frequency measurements from 10 kHz to 225 MHz. The national reference can therefore support both elapsed-time measurements and the calibration of electronic frequency standards.

The 2026 reform did not introduce a seasonal clock change or alter everyday civil time. Its significance is underneath the display. Official time is now tied explicitly to a metrological chain that can be related to the International System of Units and Coordinated Universal Time. Costa Rica moved from a history in which observations were carried by a student to the printing office, trains published departure minutes in newspapers and public clocks could disagree, to a system in which the national second is maintained through atomic standards.

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