site.btaBulgaria to Welcome Spring and Switch to Daylight Saving Time by End-March, Physicist Says

By the end of March, Bulgaria will mark the start of astronomical spring and switch to daylight saving time, while a minor ‘planetary parade’ is expected to be observable in April and May, physicist Pencho Markishki told BTA.

Astronomical spring will begin at 4:46 p.m. local time on March 20, when the Sun crosses the vernal equinox point in the constellation Pisces. Until June 21, it will rise progressively higher over the Northern Hemisphere, leading, along with increasing daylight duration, to gradual warming. In the Southern Hemisphere, autumn will begin.

The celestial equator coincides with Earth’s equatorial plane and divides the celestial sphere into northern and southern halves, while the ecliptic represents the Sun’s apparent annual path. Due to the tilt of Earth’s axis relative to its orbit, the two circles intersect at an angle of about 23°26′, resulting in seasonal changes and variations in day length.

Around the equinox, daylight increases at its fastest rate – by nearly three minutes per day. Although day and night are theoretically equal, at Bulgaria’s latitudes daytime exceeds nighttime by about 8.5 minutes. This is due to atmospheric refraction and the convention of measuring sunrise and sunset by the Sun’s upper edge.

On March 20, 2026, daylight will last 12 hours, 8 minutes, and 32 seconds – about eight minutes longer than the astronomical 12 hours.

At the end of March, Neptune (March 22) and Saturn (March 25) will be in conjunction with the Sun, making the events unobservable. In April, a morning planetary alignment involving Saturn, Mars, and Mercury will begin to form, becoming more favorable for observation in May, although Mercury will have already left the relevant sector by then.

Around April 20-21, the three planets will be in close conjunction, but the event will not be visible from Bulgaria due to the advancing morning twilight.

At 03:00 a.m. on March 29, the country will switch to daylight saving time, with clocks set one hour forward.