Twice a year Bulgaria goes through a "mini shock" of biological time – the spring switch to daylight saving time and the autumn return to standard astronomical time. Although formally this is only a one-hour change, for the body it is a "small time zone shift" that can affect sleep, the cardiovascular system, mood and productivity. More and more doctors and chronobiologists warn that "clock acrobatics" has its price, especially for people with chronic diseases and for children.
What the time change in Bulgaria means
Bulgaria follows the common European practice of changing the clocks – at the end of March the hands are moved one hour forward to introduce "summer time", and at the end of October they are turned back to standard astronomical time. Officially, the motive is more efficient use of daylight, energy savings and synchronization with other EU countries.
In practice, however, this administrative change "shakes" the human internal clock, which is guided not by the digits on the display but by sunlight and regular habits. When the day suddenly starts "earlier" on paper, the body has to reset its sleep–wake cycle, hormone secretion and metabolic processes. This forced synchronization can take from several days to weeks, depending on age and health status.
The circadian rhythm and the "internal clock"
The circadian rhythm is the 24‑hour internal "metronome" of the body that regulates when we feel sleepy, when we are most productive, how body temperature changes, appetite and the release of key hormones such as melatonin and cortisol. It is controlled by a neuronal center in the brain that is sensitive to light and is "reset" daily by sunrise and sunset.
When the clock is moved one hour forward, the internal rhythm cannot "jump" that fast. Many people describe the feeling as "mild jet lag" – difficulty falling asleep at the new time, morning sleepiness, irritability and decreased concentration. With the autumn move back, some people adapt more easily, but others complain of early awakening and shifts in appetite and mood.
So‑called "owls" – people who naturally fall asleep later – and children, whose sleep and eating schedules are strongly tied to routine, are particularly sensitive. For them, even a one‑hour change can lead to noticeable behavioral changes: restlessness, more frequent outbursts, lack of concentration at school.
Effects on sleep and quality of rest
The most immediate effect of the clock change in Bulgaria is on sleep. The spring transition to summer time literally "steals" one hour of night rest if people do not prepare in advance. This leads to a shorter first night, more superficial sleep and higher daytime sleepiness in the following days.
Chronic sleep deprivation, even by one hour a night, is associated with an increased risk of metabolic disorders, weight gain, high blood pressure and impaired concentration. For people who already sleep less than the recommended 7–8 hours, this additional "hour of deficit" can tip the scales toward marked fatigue and errors in daily activities.
Doctors remind that "sleep is not a luxury but a biological necessity" and that for many people the spring time change actually means "even less sleep during a period when the body needs to adapt to changing light and temperature". According to them, underestimating this effect lies behind part of the complaints of "spring fatigue".
Cardiovascular risks and incidents
Numerous international studies show that in the days after the spring switch to daylight saving time there is a small but statistically significant increase in cardiovascular incidents – heart attacks, strokes, arrhythmias. Although the differences are not dramatic for an individual, at the population level this effect becomes a real health risk.
Cardiologists explain this by a combination of three factors: sudden change in sleep schedule, increased stress and workload in the first working days after the switch, and poorer control of chronic diseases in people who do not adjust their medication intake to the new time. For sensitive patients, even a slight "shift" in medication timing and sleep can be a problem.
Some specialists describe the spring change as a "controllable but real stress test for the heart". That is why they recommend that people with hypertension, coronary artery disease or previous heart attack be particularly careful around the time change – monitor their blood pressure, not skip medications and avoid extreme exertion.
Impact on mental health, concentration and safety
Beyond physical effects, the time change also affects mental health. Disrupted sleep and rearrangement of morning and evening light can worsen symptoms of anxiety and depression in predisposed individuals. Some psychiatrists report "destabilization" of otherwise stable conditions precisely during the time change periods.
Attention and reaction times worsen in the short term, increasing the risk of workplace accidents and traffic crashes. Drivers who go to work in the dark and in a state of sleep deprivation are more prone to errors and nodding off at the wheel. The first few days after the switch to summer time are particularly risky.
Teachers and psychologists note that school‑age children also "pay the price" of the time change – they are more distracted, more prone to conflict and less productive in the morning. This is especially true for pupils who travel early and get up at a time when their bodies still "think" it is night.
Who is most vulnerable to the time change
Although many healthy adults adapt relatively quickly, there are groups for whom the time change in Bulgaria is a more serious challenge. Foremost are people with cardiovascular diseases, hypertension, heart failure and rhythm disorders, for whom any additional strain and sleep loss carries risk.
A second risk group are people with chronic sleep disorders – insomnia, sleep apnea, restless legs syndrome. For them, even a small shift in schedule can lead to a long period of unstable sleep and daytime sleepiness. Shift workers, who already live with a "disrupted" circadian rhythm, are particularly vulnerable.
The third group are children and the elderly. Children’s bodies react strongly to changes in sleep and meal schedules, while in older people adaptation mechanisms are slower and chronic illnesses more numerous. For them, careful planning of the daily routine in the week around the time change is especially important.
Practical tips for easier adaptation
Sleep specialists and chronobiologists suggest several simple but effective strategies that Bulgarians can use to ease the transition to and from daylight saving time. The general principle is "smaller steps but in advance" rather than trying to make up the hour in a single night.
The first recommendation is to shift bedtime and wake‑up time by 10–15 minutes earlier (in spring) or later (in autumn) each day starting 3–4 days before the time change. By the moment of the official change, the body has already "covered" part of the distance and the stress is smaller. This approach works especially well for children.
The second key measure is strict sleep hygiene: avoiding heavy food and alcohol in the evening, limiting screens at least an hour before bedtime, keeping the bedroom dark, quiet and cool. A short walk in daylight in the morning after the change helps the internal clock to "reset" more quickly to the new schedule.
The third recommendation is to avoid abrupt changes in the daily schedule in the first days after the switch. If possible, demanding tasks should be scheduled for later in the day when the body is more fully "awake". Drivers should be particularly careful, avoid driving while overtired and plan short breaks on longer trips.
What people with chronic diseases can do
For people with chronic diseases, the time change should not be a random event. Doctors recommend advance consultation – especially for patients with previous heart attacks, strokes, arrhythmias, severe hypertension or diabetes. Together with their doctor they can discuss whether a temporary shift in the timing of medication is needed.
In the days around the change it is important to monitor key parameters – blood pressure, heart rate, blood sugar – and to avoid situations of strong stress and physical overexertion. If new or unusual symptoms appear – severe headache, chest tightness, shortness of breath, speech or vision disturbances – medical help should be sought immediately, without waiting for it "to pass on its own".
Psychiatrists and psychologists advise people with anxiety and depressive disorders not to change their treatment regimen on their own but to discuss any sleep and mood difficulties with their doctor. If needed, short‑term support can be added – relaxation techniques, cognitive‑behavioural strategies for sleep and, in some cases, medication.
The debate about the future of time changes
In Bulgaria, as in other European countries, there has been a long‑running discussion about whether the twice‑yearly time change should be abolished. Arguments "for" keeping it are based on energy savings and better use of daylight, especially in after‑work hours. Arguments "against" focus on health risks, sleep disruption and difficulties for vulnerable groups.
More and more sleep and cardiology specialists stress that "the body cannot be switched like a digital watch" and that every artificial intervention in the circadian rhythm has its price. They see a sustainable solution in choosing a single permanent time to which society would adapt once and for all, instead of "paying" with fatigue and health risks twice a year.
Until such a political decision is made, individual responsibility remains – to treat the time change not as an insignificant calendar detail but as a predictable stressor for the body that can be softened with sensible planning, good sleep hygiene and careful management of chronic conditions. As specialists sum it up: "The clock changes in a minute, but sometimes the body needs weeks to catch up".