On that date, Chris Pronger was the only current Flyer in the NHL, and he was a rookie. James van Riemsdyk was 4 years old.
Like all the Flyers' recent losses, this was marked by turnovers, inconsistent effort, a rash of unwise penalties and a toothless power play, now 2-for-32 after an 0-for-5 effort.
"We were off today," coach Peter Laviolette said. "We're having a difficult time getting out of a rut."
Are they ever.
Callahan scored on the Rangers' first possession, just 51 seconds into the game against the Flyers' first unit.
He scored again about midway through the first period after Mike Richards' penalty ended a Flyers' power play and, eventually, created one for the Rangers.
Ville Leino's fancy move during a four-on-four led to the two-on-one rush that became the Rangers' third goal.
Callahan then simply picked up a puck Kris Versteeg mishandled in front of the Flyers' goal to make it 4-0 just over 6 minutes into the second period.
The debacle provided a composite of what has gone wrong with the Flyers since the All-Star break.
So, the fix?
Pronger said portions of the team have abandoned the system Laviolette installed when he took over a little more than a year ago - a system that led the team from desperation to a long run into June, two wins shy of a Stanley Cup.
"June is a long way off from right now," Pronger said. "You forget what it took to get there.
Pronger assigned blame to everyone, but he and his fellow defensemen especially don't like what they see in front of them.
"Some guys are on one page, other guys are on another page," Pronger said. "Turnovers are what's killing us. We've got to get the puck in deep, get on the forecheck and get some sustained pressure in the offensive zone and start grinding on teams the way we have in the past. Until we do that, teams are going to pick us apart, like they have."
Not on the same page?
"Different chapters, maybe," Richards said. "When you have a lot of success, sometimes you get away from the program, what the coach is harping on doing, start letting things slide. That could have been evident before this game. It was very evident during it."
The evidence, in Richards' eyes: "We were late getting to pucks. We were turning pucks over. Missed coverages. We didn't clear pucks. Took penalties at bad times."
Callahan's third goal ended the day for Brian Boucher, who, in his second start in six games, was replaced by Sergei Bobrovsky with 13:32 to play in the second period.
Unflappable, Boucher warned, "We need to stick together and not overreact to a delicate situation."
He pointed to the team's 40 wins, its depth, its talent.
None of that seems relevant after the first loss by this large a margin in more than 4 years.
"It's a test of our character," Pronger said. "We've got to show our mettle."
That's a fine sentiment. Doing so would have meant a lot yesterday. The Flyers had hoped to salve the sting of consecutive home losses earmarked by blown leads, March games that built upon the faltering February theme of partial focus and undisciplined play.
They wanted to begin to rebuild a lead in the Eastern Conference that once stood at nine points but now is down to two.
They needed to do all these things in their second game within a 24-hour span, their third in 4 days, their third of four games in 6 days, the start of a grueling, 15-in-29-days stretch, all while recovering from a nasty flu bug that has ripped through the team.
The last three losses have come against teams on or near the playoff bubble, teams performing in playoff mode - the most dangerous sort, really.
"The teams that we are playing now are in the exact same position we were in last year," Pronger said. "They need wins desperately."
Teams such as the Rangers, seventh in the conference before yesterday but only two points ahead of ninth-place Buffalo, who beat the Flyers on Saturday. The Rangers were five points ahead of Toronto, who won in Philadelphia on Thursday.
Callahan scored with 15:40 to play in the third, a goal he appeared to kick in. A review determined the goal to be legitimate, giving him 20 for the season.
Later in the third, Artem Anisimov caught the Flyers in a line change, broke free and beat Bobrovsky to make it 6-0. Mats Zuccarello scored his second of the game with 73 seconds left.
Afterward, stunned and sullen, Richards could manage no more than hopeful resolve and appropriate aphorisms: "Move on. Stick with the program. Don't try to do too much. Don't start pointing fingers."
There might not be enough fingers.
Jeff Carter missed his second game out of three with a flu relapse. Carter, tied for the team lead with 28 goals, missed Thursday's game with the flu, was excused from practice Friday to attend his grandfather's funeral in Canada, returned and played Saturday. Shortly after beginning his pregame routine in New York, Carter stopped, dressed and left the rink . . . The teams combined for 17 penalties . . . Jody Shelley clobbered Brian Boyle in a fight midway through the first period . . . The result might have been worse. A second-period goal by Sean Avery was disallowed after it was determined Avery kicked it in.