Gregor's Day, the Slovenian version of Valentine's Day, is the day when, according to folk tradition, birds get married, and the day when the first day of spring was celebrated during the Julian calendar. Gregor's Day brings not only spring and light, but also a lot of social events, including at the Ljubljana Castle, where the spring festival will be celebrated this year with two events, namely a fairy-tale-creative meeting from the series Nature in Fairy Tales and a concert by tango performers, the Beltango quintet .