Are birthdays celebrated in Glorantha?

We have a Gloranthan calendar with a lot of religious holy days and hight holy days. 
But birthdays a thing in Glorantha?

While digging in old ducuments doing genealogy in real life i discovered that a lot of people doesn´t seem to have known the birthday of they parents or partners in the 17 and 18 hundreds. "about 75 years" is given in the church book when they died and had to be buried. But that persons spouse and children were very much alive at that time. But they doesn´t seem to have known the exact birthday of their partner/parent. 

Do Gloranthans know the date they were born? 
Do they celebrate their birthdays with their familiy?
Or is initiation day more important?

Are there good omens whe you were born on specific days, or bad omens when you were born at another?
Will it make a difference if for instance a girl is born on Ernaldas Holy Day, or on Ty Kora Teks Hold Day?

What does a glorantha birhday party look like?