Date math makes me crazy

I just don’t understand this and leap years make this problem obvious to
me…

test = DateTime.now
=> #<DateTime: 53017684949923739/21600000000,-7/24,2299161>

test.strftime("%Y-%m-%d")
=> “2008-02-25”

test = DateTime.now + 365
=> #<DateTime: 70700758603797619/28800000000,-7/24,2299161>

test.strftime("%Y-%m-%d")
=> “2009-02-24”

seems reasonable, off a day because of leap year…

test = DateTime.now + 1.year
=> #<DateTime: 1469323689922559749/43200000000,-7/24,2299161>

test.strftime("%Y-%m-%d")
=> “88409-12-04”

how do I add a simple year?

Craig