ActiveSupport DateTime.to_time (yesterday vs now)

Rails
1

What’s so strikingly different between “yesterday” and “now”?

irb(main):010:0> require ‘activesupport’
=> []
irb(main):014:0> DateTime.yesterday.to_time.class
=> Time
irb(main):015:0> DateTime.now.to_time.class
=> DateTime