How do you expect a meteor shower?

Answer 1

Meteor "showers" happen when the Earth passes through the orbit of a comet, or where a comet once was. Most of the meteors are dust-sized, and when a comet approaches the Sun, the Sun's heat and light melt some of its ice and blow the dust and vapor into the "tail" of the comet.

But the dust continues along in the same orbit as the comet; just a little slower.

The ancient comet's orbit passes near the Earth at one spot along the Earth's orbit, and the Earth goes through pretty much the same path each year. So meteor "showers" happen on the same day each year.