It seems like every company is using Back to the Future Day for fun or promotional purposes, including Google.

While Lyft is offering free DeLorean rides throughout New York City on 21 October 2015, Nike has announced it is collaborating with the Michael J Fox foundation to release limited-edition, power-lace Nike Mags next spring. Determined to not be left out of the loop, Google has joined in on the Back to The Future Day celebrations.

The company via Twitter announced new Gmail themes, and it included a link to them, but when clicked upon, the link doesn't open to a page with themes but rather a "confidential" PDF about something called Project Flux.

Get it? As in, the Flux capacitor, which let Marty McFly, played by Michael J Fox, time-travel in a DeLorean DMC-12 from 26 October 1985 to 21 October 2015 in order to get his son out of a jam in the 1989 film Back to The Future II.

Google's joking with us of course, but it is an elaborate joke indeed. The company's "leaked" PDF features slides with factitious science and a mock prototype car that looks to be some sort of spawn between a DeLorean and Google's self driving car. There's also many references to the film trilogy and even a production timeline laid out.

Google's time-traveling car is suppose to go into production today in Ireland. The company "plans" to start 88 public tests by mid-2016. But that's just another gag reference, if you didn't notice, because the DeLorean in Back to the Future must go 88 miles per hour in order to travel through time.

Check out Pocket-lint's Back to the Future hub to see what other kooky things are happening.