“March” or “Martis” is a very old custom.
It is believed to have its roots  in Ancient Greece and more specifically in the Eleusinian Mysteries, where the mystics tied a thread, the Kroki (=thread), to their right hand and their left leg. 

Nowadays at the first day of March, parents put a bracelet made of white and red thread, called a “March”, around the wrist of their children. It is made on the last day of February and worn on the first day of March, before the children go outside. In some areas, the “March” is worn around the big toe as a ring, in order to protect its owner from falling.
According to tradition, this bracelet helps the faces of children not to get burned by the first sun of spring, which is the most burning of the year. At the end of the month they take it off and they hang it on rosewood or on trees in order for swallows to take them and build nests.
But this tradition is also well known in all Balkan countries.

 

In Skopje it is called “Martinka” and in Albania has the name “Verore”.

When the people take off the bracelets, they hang them on a tree in order to transfer this way something of its magical power and give the tree flowering. Years ago, some people used to  hide them under stones and if the next day there was a worm next to them, that was considered a good omen for the rest of the year.

In Bulgaria, people wear a white- red string ornament, while in some areas they place a red and white cloth outside the door in order “grandma- Marta (as they call March) not to burn them “. “Martenitsa” is in the system of the Bulgarian folk belief an amulet, which they often offer as a gift.

In Romania, the same custom is called “Martizor”. The red thread symbolizes the love for the beauty and the white the purity of a plant that blooms in March.
Indeed, there is also a related myth in which the Sun descended to Earth to take part in a feast. Though it had taken the form of a man, a bad dragon trapped him, and the world fell into deep darkness.
Once a young man killed the dragon and his blood coloured the snow. The bracelet of March comes to remind people of his sacrifice.