date: YYYY-MM-DD parsed incorrectly

[rrconkle]

When the day in the YYYY-MM-DD format is 1 character long, an extra zero is added to the end

$ uu-date -d 2000-1-1
Mon Jan 10 00:00:00 2000
$ uu-date -d 2000-1-4
uu-date: invalid date '2000-1-4'