For this Yalda there are 146 different names on Yasni.
Most common last names for Yalda are: Irani, Safavi
In the ranking of the most common first names Yalda is on position 4445.
Yalda is the longest night of the year = the beginning of winter. That night after all of Iranians has special significance and is celebrated etc.
(Sent from: Mohsen)