What version of Go are you using (go version)?

go version go1.7.5 darwin/amd64

What did you do?

https://play.golang.org/p/R4HlVseTm2

What did you expect to see?

A behavior which corresponds the documentation.

Actually I expect to see an error, but the current documentation says that it should be parsed successfully.

For example February 31 and even February 99 are valid dates, specifying dates in March and May.

Documentation was introduced by CL https://golang.org/cl/14123
but that behavior was changed later by CL https://golang.org/cl/17710