Support early/mid/late <month> about duckling

[pcgreat]

thanks @serefayar Looks perfect!

[patapizza]

Hi @pcgreat, do you think you can implement this? Thanks!

[pcgreat]

@patapizza I will try my best

[Abhiroop]

@pcgreat I have the same requirement. Did you make any progress in it? Or I can try picking this up too.

[pcgreat]

@Abhiroop I am still reading the source code, and haven't made any real progress yet. You are more than welcome to pick it up

[serefayar]

@pcgreat @Abhiroop I am not sure about the implementation.

[pcgreat]

@serefayar thanks for your implementation! I did try your commits and it's a good reference for me to learn. However, I notice something weird and not sure if that's something you can fix: "late July" points to the July of 2018. Ideally, "late July" can be July of 2017, and "late February" to be Feb of 2018 (future by default)