Mothers listing children's dates of birth on academic CV?
This is common in Europe. Parents are not supposed to (and to some extent not allowed to) work during maternity or paternity leave. Thus, such periods are deducted from your phd-age, tenure clock etc. 

Quoting from the ERC Starting Grant 2017 call:


  For maternity, the effective elapsed time since the award of the first PhD will be considered 
  reduced by 18 months or if longer by the documented amount of leave actually taken for 
  each child born before or after the PhD award. For paternity, the effective elapsed time since 
  the award of the first PhD will be considered reduced by the documented amount of 
  paternity leave actually taken for each child born before or after the PhD award.


And from one of the largest commercial foundations supporting basic research in Denmark, which explicitly states that the CV should contain this information:


  In the case of maternity leave, the number of months on leave, times two, will be deducted from the seniority.
  The specific dates for the period of maternity leave must be clearly stated in the CV/resume.