A Song For My Fourth Birthday

I was out early this morning before the day was much more than a promise. Cardinals were singing from every direction. I wondered, as I always do, why?
Why are they singing as they do at springtime, but in August? Why don't I just accept their gift of song and quit wondering why?

"A day and then a week passed by:
     The redbird hanging from the sill
Sang not; and all were wondering why
It was so still ---
When one bright morning, loud and clear,
Its whistle smote my drowsy ear,
Ten times repeated, till the sound
Filled every echoing niche around;
And all things earliest loved by me, ---
The bird, the brook, the flower, the tree, ---
Came back again, as thus I heard
     The cardinal bird."
(From The Cardinal Bird by William Davis Gallagher)

Today is my youngest child's 46th birthday. He is my second son, third child. Do other mothers count the days of their children's births as their 'birth' days, too?