"We're no longer a morning day part business. We're a business throughout the day," he told CNBC's "Squawk on the Street."
While most restaurant-and-retail companies in its class are struggling to put up 5 percent growth at U.S. stores, Starbucks on Thursday reported comparable-store sales in the Americas increased 9 percent in its most recent quarter. That beat estimates of 7.2 percent, according to StreetAccount.
Starbucks has offered its breakfast customers coupons to entice them to come back later in the day, and a promotion offers bonuses to Starbucks Rewards members when they load cash onto their loyalty card.
Rolling out mobile pay infrastructure also has significantly contributed to sales, Schultz said. The chain served 18 million more Americans in the final quarter of 2015 than it did during the same period last year, he added.
"At a time in America where every bricks-and-mortar retailer is struggling just to be even or parity in traffic, not only are we driving comp-store sales at 8 percent globally and 9 percent in the U.S., but we are driving 4 percent incremental traffic. It's unheard of at our scale," he said.
Starbucks reported quarterly earnings on Thursday that topped expectations, but revenue missed estimates and a key metric in China and Europe disappointed Wall Street.
The coffee giant posted fiscal first-quarter earnings of 46 cents per share on $5.37 billion in sales, which were down 29 percent and up 12 percent from the previous year, respectively.
Wall Street expected Starbucks to post earnings of 45 cents per share on $5.39 billion in revenue, according to a consensus estimate from Thomson Reuters.
Its shares were down more than 1 percent on Friday.
The chain's comparable-store sales around the world increased 8 percent in the quarter, beating estimates of 6.9 percent.
However, its comparable-stores sales growth in the China and the Asia-Pacific region came in at 5 percent, falling short of expectations. Comparable-store sales growth in Europe also missed estimates as overall segment revenue fell 6 percent year over year to $313 million.
Schultz said those who choose to read the China data as a deceleration are misinterpreting it, noting the company has logged 12 straight years of positive comp-store sales and traffic there. He added that the company is beating its internal expectations in three areas: sales-to-investment ratio, operating income and traffic.
Earlier this month, Starbucks announced it planned to open 500 stores this year in China — its second-largest market. The move comes amid a slowdown in the Chinese economy that has contributed to worldwide market volatility this year.
Multiple retailers and restaurant chains have reported struggles in China. Still, Starbucks said its China and Asia-Pacific region net revenue grew 32 percent from the previous year to $653.6 million, helped by the acquisition of Starbucks Japan.
"To me, the momentum is still there. Who else is posting these types of comps in this environment globally?" Nick Setyan, a senior equities analyst at Wedbush Securities, said Thursday on CNBC's "Closing Bell."
Starbucks expects fiscal second-quarter earnings in a range of 37 to 38 cents per share, below expectations of 40 cents per share, according to a consensus estimate from Thomson Reuters. For fiscal 2016, it projects profit of $1.84 to $1.86 per share.
In a telephone interview after Starbucks announced earnings, Chief Financial Officer Scott Maw said the company has locked in prices on more than 90 percent of its coffee needs.
The company's shares have fallen about 3 percent this year, beating the broader market. Still, the stock has climbed more than 40 percent in the last year.
— Disclosure: Wedbush Securities is a market maker in the securities of Starbucks.
— Reuters contributed to this article.