Instruction
1
The phrase "day of birth" consists of two words in nominative and genitive cases, respectively. The second is a dependent word with respect to the first. Analogues: "Constitution Day", "Groundhog Day", "Day of Cosmonautics", "Day of the air force".
2
The second word is technically the indirect complement, and in fact – the definition describing the first. A day or what? – of birth.
3
The noun "birth" is used in the singular, in the genitive case. Refers to the average genus, is inclined to the second type, therefore, has the ending "I".
4
Verbal nouns, which include the word "birth" have two spellings: "ie" or "rd": a blink – moment, movement – the movement. So the options are: birth – birthdayi.e. In the phrase, respectively, will be used variants of "day of birth" and "day birthdayme."
