I need my movie to say 2020

I'm pretty sure this is standard practice on IMDB.

See, for example 

All The Boys Love Mandy Lane (2006)

From Wikipedia, all emphasis mine:

Originally completed in 2006, the film premiered at a number of film festivals throughout 2006 and 2007, including the Toronto International Film Festival, Sitges Film Festival, South by Southwest, and London FrightFest Film Festival. It received a theatrical release in the United Kingdom on February 15, 2008.[3] 

[...]

Despite its international attention, the film went unreleased in the United States for over seven years after it was completed; this was due to complications with its distributor, Senator Entertainment, which went bankrupt shortly after purchasing the film from The Weinstein Company. On March 8, 2013, it was announced that The Weinstein Company had re-acquired the rights to theatrically release the film in the United States. The film became available through video on demand in September 2013, and was given a limited release on October 11, 2013, through a joint contract between Senator Entertainment and Weinstein's subsidiary label Radius-TWC.

From the IMDb Help Center (linked on the Menu available on each IMDb page):
Release dates
where, among other things, it says:

Please note that the year in the title is derived from the date of earliest release. This includes any festival release dates. With this in mind you can update the year by either adding a new release date or correcting an existing one. The release date that displays directly under the title is the release date for the title display country as chosen in your content settings. 

This is, for want of a better word.... un-smart. When the movie has been shown in public, no matter how small the festival, and as long as there are paying, legally above the counter customers   but ESPECIALLY when it's a big and IMDb-recognized festival, then THAT is the year of release.
Deal!

Hi Abi,

Thanks for your post.

As mentioned, we list the titles year by it's earliest release date - as this title was released in 2019, this cannot be changed on the title. 

Thanks for understandng our policy on this. 

Joel