April 13 is the Day of Defense Industrial Complex Workers in Ukraine, the World Day of Remembrance of the Victims of the Katyn Shooting, the World Day Against Sexual Violence Against Children, the International Day of Awareness of Functional Neurological Disorders, and the International Day of Appreciation of Plants. April 13 is also a day when events took place in different historical eras that influenced the course of world, European, and Ukrainian history.
Day of the employee of the defense and industrial complex of Ukraine
This professional holiday was introduced in 2023 and is intended to honor all those who work on the creation, modernization and provision of weapons and military equipment for the Armed Forces of Ukraine and other power structures. The Cabinet of Ministers initiated the establishment of this day, recognizing the importance of system support for defense enterprises, which became critically important during a full-scale war.
With the beginning of Russia’s large-scale aggression against Ukraine, the importance of the defense-industrial complex (ODC) reached a new level. In the conditions of continuous hostilities, the need for high-tech weapons, rapid repair and rearmament of the army, the Ukrainian defense industry has become an integral part of the national security strategy. Enterprises that are part of the State Concern “Ukroboronprom” and other private and state-owned companies expanded production, switched to military rails, increased the production of ammunition, armored vehicles, drones, and artillery systems.
Employees of the defense sector are engineers, technicians, designers, operators of complex machines, experts in logistics, cyber defense, developers of the latest military technologies. Their work is no less important than the actions on the front lines. It is these people who provide the soldiers with the necessary means of protection, offensive and defensive, often working in extremely difficult conditions, sometimes under the crosshairs of enemy fire, in a 24-hour mode.
Digital facts
More than 100 enterprises in the public sector and hundreds of private companies are involved in the production of military equipment in Ukraine.
As of 2025, according to official reports, the Ukrainian defense industry has increased the production of some types of weapons by 2-4 times.
In 2024, Ukrainian defense enterprises for the first time started serial production of cruise missiles and naval drones of their own development.
In 2023-2024, joint production projects with partners from NATO countries (in particular, with the USA, Germany, Poland, Turkey) were launched.
World Day of Remembrance for the Victims of the Katyn Shooting
Every year on April 13, the world commemorates the victims of the Katyn massacre – one of the most tragic pages in the history of the 20th century. On this day, more than 22,000 Polish citizens are remembered, shot in the spring of 1940 by the Soviet NKVD on the order of the highest leadership of the USSR. Among the dead were officers of the Polish army, policemen, border guards, as well as intelligentsia – teachers, doctors, lawyers, priests. Most of them were captured by the Soviets after the partition of Poland between the Third Reich and the USSR in September 1939.
Shootings took place in several places – in the Katyn Forest near Smolensk, in Kalinin (now Tver), Kharkiv, Kyiv, Minsk, as well as in a number of other regions of the USSR. All these places had one thing in common: the extrajudicial destruction of prisoners of war, who were the intellectual and moral elite of the Polish nation. The body of the Polish state had to be bled – and Katyn became a symbol of this Soviet crime.
For many decades, the fact of mass murder was hushed up or distorted. The Soviet authorities denied their involvement in the crime and blamed the Nazis. Only in 1990 did Moscow officially admit that the executions were carried out by the NKVD. However, to this day, Russia does not classify this crime as genocide and has not declassified all the archives, which causes deep indignation in Poland and around the world.
April 13 is the day when Poland, Ukraine and other states that honor the victims of totalitarianism return again and again to this painful episode. In Ukraine, in particular, they honor the memory of those who were killed in Kharkiv and Kyiv, because it was here that parts of the Katyn crime took place.
On this day, not only the dead are commemorated, but also the lessons of history reminding: political repression, destruction of elites, ideological hatred are features of a totalitarian regime that must never be repeated. Katyn is not only a tragedy for Poland, but also a common European wound that calls for memory, truth and justice.
Facts you should know
The World Day of Remembrance of the Victims of the Katyn Shooting is celebrated in accordance with the resolution of the Polish Sejm from 2007.
According to research by the Institute of National Remembrance of Poland, about 4,400 officers were shot in Katyn Forest, over 3,800 in Kalinin, over 3,700 in Kharkiv. The rest were destroyed elsewhere.
In 2010, a Polish delegation led by President Lech Kaczyński tragically died on their way to commemorate the 70th anniversary of the Katyn crime. It became another national tragedy of Poland related to Katyn.
Katyn remains a symbol of the falsification of history, the devaluation of human life and the importance of historical truth.
World Day Against Sexual Violence Against Children
This day is one of the most painful in the world human rights calendar, because it concerns a topic that is difficult to talk about, but even more difficult to remain silent. Its aim is to draw public attention to the scale of child sexual abuse, break the taboo surrounding the issue, support victims and stimulate action at all levels, from families to governments.
The day arose as a public initiative and gradually gained international resonance. Its date is connected with the high-profile case of the French priest-preacher Bernard Prein, who was exposed in crimes of sexual violence against minors. It was on April 14, 2011 that he appeared before the court. This case became the starting point for a new public discussion of systemic violence, particularly in church structures.
Today, this day goes far beyond individual cases. He reminds that sexual violence against children is not an isolated crime, but a systemic threat that has its forms in different countries, cultures, and social strata. According to WHO estimates, at least one in five girls and one in thirteen boys in the world are victims of sexual violence before the age of 18. In most cases, crimes go unsolved due to shame, fear, pressure or distrust of the system.
Ukraine is no exception. In the conditions of war, the threats of sexual violence against children only increased. Children who have survived occupation, deportation, stay in closed institutions or become victims of human trafficking are particularly vulnerable. Rape, molestation, sexual exploitation – these crimes have catastrophic consequences for the child’s psyche and often break their lives forever.
On World Day Against Sexual Violence Against Children, human rights activists, educators, media and government structures emphasize the need to speak openly: about the harm of silence, about the importance of sex education, about the responsibility of adults, about trust and a safe space for children. This day is not just about horror, but about changing the culture of silence to a culture of protection.
Facts you need to know
According to the WHO, more than 120 million girls in the world have experienced sexual violence before reaching adulthood.
In 80% of cases, crimes are committed by persons who are familiar with the child or are related to him through family, educational or other relationships.
In Ukraine in 2022, more than 700 criminal proceedings regarding sexual violence against children were registered. The real figure may be much higher due to the hidden nature of the problem.
In many countries, in particular, in Ukraine, approaches to child protection are being reformed — special “green rooms” for interrogation are being created, responsibility is being strengthened, and hotlines are working.
Prevention, timely detection, legal and psychological support, sexual education are the main tools for combating this form of violence.
International Functional Neurological Disorders Awareness Day
This day is designed to draw attention to one of the least understood, but at the same time quite common categories of neurological diseases — functional neurological disorders (FNR). They are characterized by the presence of symptoms that appear to be the result of organic lesions of the nervous system, but do not have a clear structural cause detected by traditional methods of neuroimaging or laboratory diagnostics. Patients with FNR may have symptoms such as tremors, convulsions, limb weakness, disturbances in gait, speech, vision, memory, or even epileptic seizures that are not confirmed by EEG.
FNRs are real and debilitating conditions, but patients often face mistrust, stigma, and delays in diagnosis. Due to the complexity of understanding the mechanisms of these disorders, doctors do not always correctly identify them, which can lead to incorrect treatment or even accusations of malingering. Although PNs were once viewed solely as psychogenic disorders, modern science recognizes the complex interplay between the brain, body, and psyche.
Recognizing and being aware of FNR is the first step to better patient support. That’s what this day is for: to debunk myths, give voice to people living with this diagnosis, and call for better understanding among health professionals, society and governments.
Facts you need to know
According to research, about 6% of patients in neurological clinics have FNR.
FND can occur at any age, but is especially common in young women.
The condition is not a simulation or fiction. Symptoms occur automatically, without the patient’s conscious control, and are the result of changes in the functioning of the nervous system, and not of its anatomical damage.
Diagnosis is based on clinical signs that have a certain specificity (for example, variability of symptoms, their disappearance under distraction), and not on the exclusion of other diseases.
The main approaches to treatment are a multidisciplinary approach: physical rehabilitation, cognitive-behavioral therapy, mental health support, and sometimes medication correction of accompanying depression or anxiety.
The symbol of FNR awareness is a yellow-orange ribbon, and the global campaign is known under the slogan #LetsTalkFND.
International Plant Appreciation Day
It’s a symbolic occasion to remember how deeply human life depends on plants — and how often we take it for granted. On this day, campaigns to support the preservation of flora, eco-educational events, floristic exhibitions, school projects, as well as initiatives to plant trees and indoor plants are held all over the world.
And although this holiday does not have an official status of the UN, it arose as a public initiative of the ecological and botanical communities, which strive to raise awareness about the role of plants in preserving the climate, biodiversity, well-being and mental health of people. April 13 is an occasion not only to thank indoor ficus or garden tulips, but also to think about the large-scale role of plants in the system of life on the planet.
Plants provide humanity with oxygen, food, medicine, materials for clothing and construction, and also protect the soil, regulate temperature, form climatic zones, and support the lives of millions of other organisms. In the medical sense, up to 70% of all modern medicines are of plant origin or were created on the basis of plant components. In a psycho-emotional sense, plants have a positive effect on mood, concentration, sleep, and even cognitive functions.
Against the background of climate change, deforestation and loss of biodiversity, it is the plant world that requires our deepest attention and support. That is why on April 13 you should not only admire the flowers, but also take concrete actions: plant a tree, support the botanical garden, replace plastic decorations with live greenery, explain to children why the grass under the window is not just grass.
Interesting facts
Plants make up about 80% of the Earth’s total biomass, while humans make up only 0.01%.
In one day, an adult tree can produce enough oxygen for three people to breathe.
The average indoor plant humidifies the air, reduces the noise level and absorbs pollutants — this is confirmed by NASA research.
Scientists from Tel Aviv University have proven that some plants are able to “scream” in the ultrasonic range when they lack water or are injured.
Each hectare of healthy forest absorbs 1 to 10 tons of carbon dioxide, the main greenhouse gas that causes global warming, every year.
Historical events on this day
1204 Crusaders led by Pope Innocent III captured Constantinople, the capital of the Byzantine Empire. This blow to the Greek Orthodox world not only led to the brutal looting of the city, but also finally deepened the split between the Eastern and Western churches. The capture of Constantinople became one of the most controversial events of the Fourth Crusade.
1598 In 1910, King Henry IV of France signed the Edict of Nantes, a document that for the first time recognized French Protestant Huguenots as civil rights, including the freedom of religion within certain territories. This act was a historic compromise after decades of religious wars between Catholics and Protestants in France.
1870 In 2016, one of the largest and most influential museums in the world – “The Metropolitan” – opened its doors in New York. It was founded by a group of American businessmen, artists and philanthropists as a museum open to the general public. Over the years, his collection has grown to more than two million works of art from around the world.
1923 In 2015, the Wembley Stadium was opened in London, which later became a symbol of English football and one of the most famous arenas in the sports world. The stadium was opened for the British Imperial Exhibition, and the first FA Cup final held here drew almost 200,000 spectators.
1953 The first novel of the British writer Ian Fleming “Casino Royale” was published in 2015. It was from this book that the story of one of the most famous literary and cinematic characters of the 20th century – James Bond, agent 007 – began.
1960 In 2008, France conducted another test of a nuclear bomb — this time in the Sahara desert in Algeria. It was part of France’s nuclear weapons program, which sought to establish itself as an independent nuclear power outside of NATO and American control.
1975 In 2015, a civil war broke out in Lebanon that lasted 15 years and cost the lives of more than 100,000 people. The war began as a conflict between Christian and Muslim factions, but over time regional players, including Israel and Syria, became involved.
1986 Ivan Paul II became the first Pope to officially visit the synagogue. The visit to the Great Synagogue of Rome became a powerful gesture of dialogue between Christianity and Judaism and a signal to overcome historical prejudices and anti-Semitism.
1990 2008, 47 years after the crime, the Soviet Union officially recognized its responsibility for the Katyn tragedy. The TARS statement confirmed that the shootings of Polish officers in 1940 were indeed carried out by the NKVD on the direct orders of the Soviet leadership.
2014 year in at. The President of Ukraine, Oleksandr Turchynov, announced the start of the Anti-Terrorist Operation (ATO) in eastern Ukraine. This was a response to armed aggression by Russia and pro-Russian militants in the Donetsk and Luhansk regions, and marked the beginning of a new phase of the war.
2022 The Defense Forces of Ukraine struck the flagship of the Black Sea Fleet of the Russian Federation, the missile cruiser “Moskva”. The ship was hit by two Neptune missiles and subsequently sank. It became one of Russia’s most high-profile losses in the naval war, breaking its naval dominance near the coast of Ukraine.
