May Fool!

It's here, here,
here again.

Time to joke,
time to scheme.

Devious plans start appearing,
Evil people start planning.

Pouring water into pails,
Putting insects into mails.

To fool, to joke, to succeed.
was all in people's mind indeed.

Finally it is here.

"Joe, your pants have a big hole!"
"Jane, there's no school tomorrow!"

People start laughing,
while the rest start crying.

Now I wonder,
why did my friend insist it's called May's Fool.
When it's on April the first?