How can we Fool the Rooster?

Written when the clock was set ahead one hour on April 1, 1918.
  
  
Our Rooster wakes at half-past five
And crows with all his might,
He tries to wake the people up
Before the day is light.
When Daddy hears the rooster crow
He knows he should awake
And light the kitchen fire, so Ma
Can cook the Johnny cake.
  
Now, maybe we can fool my Dad
That it's half-past five when it's half-past four,
And maybe the system's the best we have had
To fool some thousands of people or more;
But, how can we fool that rooster?
  
I have always thought our rooster had
A clock inside of his head,
And I don't know how we can fix it so
We can set the clock ahead.
I asked my Dad, and he said to me,
"Why, son, you surely know
A rooster's instinct wakens him
And tells him when to crow."
  
Now the hands of the clock we can turn ahead,
We can fool the people and feel content;
But the thing that worries me night and day,
And on which my entire thought is bent
Is, how can we fool that rooster?