What's the significance of Mr. Gataeu's clock in Benjamin Button?

Question

At the beginning of the 2008 movie The Curious Case of Benjamin Button, an old woman named Daisy tells her daughter a story about a blind clock-maker named Monsieur Gateau who has lost his son in the 1st World War. When he's commissioned to design a clock for a train station nearby, he builds one which has time running backwards. When he's asked why he did something like that, he answers that so that the people lost in the World War would come back home again, and live the life they meant to have, including his own son.

I made it that way.
So that perhaps the boys that we lost in a war
might stand and come home again.
Home to farm, work, have children. To live long, full lives.
Perhaps my own son might come home again.

Then it's said that Mr. Gataeu was never seen again.

Then the woman asks her daughter to get her diary and read it to her. The diary is about the life of Benjamin Button. However, Button's life and Mr. Gataeu's story seems to have no relation at all. Or is their any link between these two seemingly distant stories?

Answer 1

The clock reflects Benjamin Button's life.

While Mr. Gataeu made the clock like that to symbolize the young souls lost in the war, the movie parallels the clock with Button's life journey. The clock runs backwards, much like Button's. While the rest of the world moves forward, the clock is the only thing that moves towards the same direction as Button. The clock is unveiled to public in 10th November 1918, a day before Button is born. The clock is removed (replaced by a new clock) in 2002, and Button dies in 2003. Both existed almost the same number of years in this world.

in 2002, they put up a new clock in that train station.
And in the spring of 2003, he looked at me and I knew that he knew who I was.
And then he closed his eyes as if to go to sleep.

Answer 2

Benjamin is actually the reincarnation of Mr. Gateaux's son whom he lost in the first world war.

He stated that he hoped that his clock by running backwards might cause his boy to come back. He did, but just not the way he thought it would.

Source: TV Tropes.

Answer 3

The whole movie was based on backward time or reverse time. The clock was only a symbol of Benjamin's backward life. The clock was very relevant to the whole story and it made the movie even sad.