Jessica Estepa

USA TODAY

Back when he was on the campaign trail, Donald Trump said to expect less from @realDonaldTrump if he made it to the White House.

Even though Trump has a whopping 28 million followers on Twitter, he insisted in March 2016, "I'm not going to be doing it very much as president."

Yet nearly 100 days into his term, the social media network remains a key way the new president communicates with the world, whether it's to defend his policies, lambast people or groups he views as getting in his way, or even conduct foreign policy.

Since he assumed office nearly 100 days ago, President Trump has tweeted 440 times. To put that in perspective, as of Sunday, April 23, he's tweeted an average of 4.68 times per day since his inauguration on Jan. 20. And that's not including retweets.

USA TODAY analyzed the patterns of Trump's tweets since taking office. Here's what we found:

Sundays are the day of (Twitter) rest

Trump is less likely to tweet on Sundays than any other day of the week. He sent a total of 55 tweets on the 14 Sundays he's been in office. The days when he's the busiest? Wednesdays (68 tweets) and Fridays (74 tweets).

His weekend trips don't really affect his tweeting

He's only slightly less likely to tweet if he's traveling to — or already at — the Southern White House. He tweets an average of 4.43 times per day on the weekends he's at Mar-a-Lago. When he's not there, he has sends an average of 5.33 times.

Inauguration was Trump's busiest day in the Twitterverse

He tweeted 12 times on Jan. 20, the most he's ever tweeted in one day while president. Most of those tweets came during a 20-minute span, from 12:53 p.m to 1:13 p.m. The tweets sounded like shortened versions of his inaugural address, such as: "The forgotten men and women of our country will be forgotten no longer. From this moment on, it’s going to be #AmericaFirst."

Since then, two days tie for runner-up. He tweeted 11 times on Feb. 8, when he urged a federal appeals court to uphold his temporary travel ban on travelers from seven Muslim-majority countries and called out Nordstrom for dropping daughter Ivanka's fashion line. He also tweeted 11 times on Feb. 15, two days after the resignation of his national security adviser Michael Flynn amid questions about his administration's ties to Russia.

Trump didn't tweet at all ... on only two days

What could have kept him away? It's not entirely clear. On Sunday, March 12, the president was in Washington and didn't have any public events scheduled. His officials were out and about convincing people to support the Obamacare replacement bill.

On Saturday, April 15, which fell on Easter weekend, the president was down at Mar-a-Lago and had no public events scheduled. Meanwhile, Vice President Pence was in Seoul and thousands of people were marching for Trump to release his tax returns. (The other day he didn't write something himself was April 7, when his only Twitter activity consisted of a retweet of daughter Ivanka.)

His most-liked and retweeted tweet was about respecting protesters

"Peaceful protests are a hallmark of our democracy. Even if I don't always agree, I recognize the rights of people to express their views," he tweeted on Jan. 22, just two days after his inauguration and the day after thousands of people participated in the Women's March.

That tweet received 393,916 likes and 82,535 retweets (possibly because it appealed to people who didn't vote for the president).

But people replied the most to a threat in ALL CAPS

On Feb. 9, the day that a federal appeals court refused to reinstate his temporary travel ban, he tweeted, "SEE YOU IN COURT, THE SECURITY OF OUR NATION IS AT STAKE!"

That tweet inspired about at least 147,000 replies.

Twitter is his bully pulpit

Trump uses Twitter as a direct line to express his beliefs. Consider his tweet that accused the Obama administration of wiretapping, which took many in Washington by surprise. "Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!" he tweeted on March 4.

In addition to jabbing at Democrats, he's also taken the unusual step of launching Twitter attacks on members of his own party. When the effort to repeal and replace Obamacare tanked in Congress, he called out the House Freedom Caucus on March 30: "The Freedom Caucus will hurt the entire Republican agenda if they don't get on the team, & fast. We must fight them, & Dems, in 2018!"

He's used it as a foreign policy tool

For instance, he pronounced "Iran has been formally PUT ON NOTICE for firing a ballistic missile. Should have been thankful for the terrible deal the U.S. made with them!" on Feb. 2.

It's also possible to see some foreign policy evolution through his Twitter feed — especially when it comes to China, the recipient of a lot of tough talk during his campaign. On Feb. 10, he said China had done little to help curtail the threat from North Korea — but on April 13, after speaking with China's leader Xi Jinping over the phone a week after their summit, he said he had "great confidence" that China could handle North Korea.

A favorite target: Fake news!

As he did during the campaign, Trump loves to rail against the media industry on Twitter. He has mentioned the term "fake news" 29 times since taking office. Of those, he used the term in all caps — "FAKE NEWS" — 20 times. (One time, though, he was retweeting an article he read by The Federalist, a web magazine popular among conservatives and libertarians, about the spread of fake news.)

Likely the most controversial of those tweets:

Speaking of The New York Times ...

If he's talking about the Gray Lady, he almost always describes it as "failing." (He's used the barb 15 times in 17 total mentions of the paper.)

Not all news is 'fake'

On the other hand, the president seems to have a special place in his cable-watching heart for Fox & Friends, the show that Fox News airs from 6 a.m. to 9 a.m. daily. He's mentioned the show 11 times since taking office (not including retweets), one time saying it was "great" compared to other "unwatchable" networks.

He's also tweeted stories and videos from the following outlets, not including retweets:

And for what it's worth: Of the 45 accounts he follows on Twitter, 16 are media organizations or conservative media personalities such as Bill O'Reilly, Sean Hannity, Greta Van Susteren and Ann Coulter. (The rest are Trump family members, Trump properties, people who work in the administration and other Trump associates.)

He may want to Make America Great Again

But he's only tweeted his campaign slogan 11 times since taking office. He's also tweeted a variation of it ("make America safe and great again") once and #MAGA, a favorite for his base, three times.

Read more:

The first 100 days of the Trump presidency

Analysis: A bumpy 100 days for Trump? Just wait for the 1,361 to follow

Ronald Reagan to Donald Trump: Comparing first 100 days of last six presidents