DateTime:to_s(:db) does not convert to UTC

ActiveRecord saves datetime fields in UTC, but in prepared statements (for select queries), the quote method does not perform the same conversion. So, for example:

(using US Eastern Time) Shift.create(:starts_at => DateTime.now - 100.minutes, :ends_at => DateTime.now - 50.minutes)
Shift.find(:conditions => ['ends_at < ?',DateTime.now])
=> [] Shift.find(:conditions => ['ends_at < ?',DateTime.now.utc])
=> Shift(Shift id: 1, starts_at: ...)

This doesn't seem the right behavior to me. Shouldn't quote automatically convert to UTC since that's the zone in which the database stores times? Could be done in the to_s(:db) formatter perhaps?