Tetiana is a Slavic female name. The short form of the name is Tania.
Tatiana is a female name of Sabine and Latin origin, a feminine diminutive of the Sabine-Latin name Tatius. Titus Tatius was the name of a king of the Sabines, an Italic tribe living near Rome, presumably from the 8th to the 1st century BC. Because the Romans met with the Sabines, Tatius remained in use in Ancient Rome and during the first centuries of Christianity, as well as its diminutive Tatianus and the feminine Tatiana.
The name then disappeared in Western Europe, but remained in the Hellenic world, and later in the Orthodox world, including Russia. It honors Orthodox Saint Tatiana who was tortured and martyred in the persecutions of Emperor Alexander Severus c. 230 in Rome. Saint Tatiana is also considered a patron saint of students. Hence, Tatiana Day is now an official school holiday for students in Russia and Ukraine.