as.Date nuance

Hi, 

  I have encountered a nuance in as.Date() behaviour that is not altogether 
obvious - not sure whether this is intended or not:

as.Date("2001-01-01error")

[1] "2001-01-01"

I.e. it ignores the rest of the characters. This happens both in 2.3.1 and 
2.4.1 versions. 

This also happens with explicit format specification:

as.Date("2006-01-01error", format="%Y-%m-%d")

[1] "2006-01-01"

                    thank you

                        Vladimir Dergachev