Google's decision to celebrate Cesar Chavez's birthday today in its Doodle, rather than Easter, has spurred some mixed reviews on Twitter.

Cesar Chavez, whose 86th birthday would be today, was a labor leader, organizer, and activist.

A lot of people are so upset that they are threatening to switch to Bing.

But it seems that Google actually hasn't created an Easter doodle since 2000. In 2011, for example, Google celebrated what would have been German chemist Robert Bunsen's 200th birthday.

Meanwhile, Bing's website features a ton of brightly colored eggs to commemorate Easter. But in Google's defense, President Barack Obama declared March 31, 2013 as Caesar Chavez Day.

Update: "We enjoy celebrating holidays at Google but, as you may imagine, it's difficult for us to choose which events to highlight on our site," a Google spokesperson tells Business Insider via email. "Sometimes for a given date we feature an historical event or influential figure that we haven't in the past."

Here are some of the tweets from people threatening to make the switch to Bing:

Congratulations @google for the first time ever, I'm using @bing as a search engine. Maybe you should rethink your google doodle. — Dreamweaver94 (@Dreamweaver94) March 31, 2013

#Google offends 1/3 of the world, by honoring Cesar Chavez' birthday in Doodle, over the resurrection of Christ? #fail I use #Bing now! — RWentonr (@RWentonr) March 31, 2013

Google doodle today celebrates Cesar Chavez, not Easter. I think it's time I migrate to Bing. Happy Easter everyone! — Ted Newton (@Ted_Newton) March 31, 2013

Happy Easter @google just downloaded Bing! You can take you Chavez doodle and your insulting snub to all Christians and go away — Annie Milliron (@AnnieM4Life) March 31, 2013

Why did Google NOT use Easter as a #GoogleDoodle on Easter Sunday 3/31/13? Maybe I should start using Bing.com — Corey Peterson (@CoreyP_eterson) March 31, 2013

Happy Easter, Google. Nice Doodle. So it's Chavez today, for real? Ok then.Settings>Search>Default>Bing>Save Changes. — Michael Krempasky (@krempasky) March 31, 2013

Google uses Caesar Chavez on Easter instead of using something Easter related? Okay, I'm switching to Bing. #tcot #google — Jordan (@LordyBiscuit) March 31, 2013

Very disappointed @google for not recognizing Easter with doodle.Perhaps Bing is better! — Liz (@lasvegasliz) March 31, 2013