Updating Date field recasts value as Time instead of Date

After upgrading to 2.1 I noticed some odd behavior with a date type attribute on one of my models. After some investigation I found that after doing an update_attributes or update_attribute affecting the date field, I got a Time type value back.

irb(main):002:0> f.charge_start_date.class

=> Date

irb(main):003:0> f.update_attribute(:charge_start_date, Date.tomorrow)

=> true

irb(main):004:0> f.charge_start_date.class

=> Time