The only problem with his memory is that the day was a lot longer ago than he recalls.
The 27-year-old last took a loss on Aug. 18, 2011, against the Phillies, and he has won nine straight decisions since then going into Thursday's start in Washington versus the Nationals.
"It was in Philadelphia," Kennedy said when asked if he remembered when his most recent defeat came. "There was a rain delay, and I didn't go back out."
Kennedy threw just three innings that day, allowing three earned runs on five hits before inclement weather sat him down.
In his 12 starts since, the righty is undefeated, including three wins this season, with a 2.34 ERA.
Going back two months further, Kennedy is 16-1 with a 2.53 ERA in his last 20 starts since last July 8.
Kennedy will try to run his consecutive win streak to double digits Thursday opposite Nationals starter Ross Detwiler, as the Nats and D-backs battle in the rubber game of their three-game set.
Washington's 26-year-old lefty delivered fantastic results in April with a 1.64 ERA, but often lacked the run support to help out his cause.
In his two wins this season, Detwiler threw a combined 11 shutout innings, while in the other two starts he didn't pitch badly, but allowed four earned runs over 11 innings and took a no-decision and a loss.
In his last outing, against the Dodgers, Detwiler surrendered two first-inning runs and eventually lost, 3-2.
"I had to battle," Detwiler said. "I hate putting my team down early. That is the toughest thing -- giving up first-inning runs. The defense really stayed behind me. It gave me a lot more confidence."
D-backs: Miley NL's best April rookie
Wade Miley began the season as the D-backs' long-man in the bullpen. But following an injury to Daniel Hudson and a couple of stellar starts, Miley was voted the National League Rookie of the Month on Wednesday.
Miley took a no-hitter into the sixth inning against the Marlins on Sunday and led all NL rookie pitchers with a 3-0 record and a 1.29 ERA with 15 strikeouts in 21 innings. His first three outings of the season came out of the bullpen, before starting twice when Hudson went on the disabled list.
"It's nice, but at the same time, we told him to keep the same hat size," D-backs manager Kirk Gibson said. "It's a great accomplishment. He's off to a great start. I'd like to see him continue to throw the ball that way. He's been huge for our team, in more ways than just being on the mound. He's made some good plays, handles the bat well, and he offers that personality. That's good. That's very good for us."
Nationals: Zimmerman to hit off tee
Injured third baseman Ryan Zimmerman, who is on the disabled list with an inflamed right shoulder, will hit off a tee on Friday, according to manager Davey Johnson.
If there are no setbacks, Zimmerman could be back on the field as soon as Tuesday against the Pirates, even without a rehab assignment.
"I'll take him cold turkey," Johnson said. "He is throwing and doing all that. He feels great, but he still has to wait and make sure he gets by this injury."
In their last seven games, the D-backs have outscored their opponents 33-18.
Jason Kubel hasn't committed an error in 56 consecutive games and leads the Majors with six outfield assists.
The Nationals led the Majors in April with a 1.78 ERA from their starting rotation.