Finding mid-point date between two dates in Python

One way would be to use datetime. Find the difference between two dates, halve it, and add it on the earlier date:

>>> from datetime import datetime
>>> a = datetime(2014, 11, 30)
>>> b = datetime(2017, 8 ,30)
>>> a + (b - a)/2
2016-04-15 00:00:00

from datetime import datetime
d1 = datetime.strptime(my_guess,"%Y-%m-%d")
d2 = datetime.strptime(their_guess,"%Y-%m-%d")
print d1.date() + (d2-d1) / 2 # first date plus the midpoint of the difference between d1 and d2  
2016-04-15