Date Extraction in Python
Stanford CoreNLP has a very good implementation of NER for date/time. 

https://nlp.stanford.edu/software/sutime.html   (demo: http://nlp.stanford.edu:8080/sutime/process)



Though this is written in Java, there are quite a few Python wrappers for this library (Such as : https://github.com/FraBle/python-sutime).  List of such libraries : https://stanfordnlp.github.io/CoreNLP/other-languages.html