Yeah, sure, we could do that. We could also use timecop. But both solutions seems overkill when all you need is to check if some attribute got updated with the result of `Time.now`. What you should do instead, is use the power of RSpec (or rspec-expectations to be more exact):
expect(post.published_at).to be_within(1.second).of(Time.current)
Doesn’t it look just beautiful?