Hi !
My data looks like this

col1 col2
1/1/2014 species 1
2/1/2014 species 1
2/1/2014 species 2
3/1/2014 species 2
4/1/2014 species 1
8/1/2014 species 1
8/1/2014 species 3
15/1/2014 species 3
15/1/2014 species 4
21/1/2014 species 5
11/2/2014 species 1
26/2/2014 species 5

And so on...

I need to figure out a way to get the time period in which I have got all the species. For eg in the above dataset, I get all 5 species by 21/1/2014.
species1- 1/1/2014
species 2 - 2/1/2014
species 3 -8/1/2014..

My dataset is huge so i cannot do it manually, i basically need the period in which i get a unique list of the complete species set.

Please help!
Thanks in advance!

Nitya