The proper way to abbreviate approximate when writing a date is with the Latin word circa, rather than approx.
The approximate date of conception was September 22nd 2009
A "circa date" is an approximate date used when the exact date of an event is not known.
The approximate date is 600 BC.
Circa = approximate
which country?
1500 BCE
Circa
The approximate date of conception was May 2nd
The approximate date of conception was July 7th.
The approximate date of conception was September 10th
The approximate date of conception was June 25th