I can't remember where I saw it, but somewhere I read that many New Yorker pieces start out, usually in the first sentence, by mentioning a specific date, or a month and year, or at least establishing a time frame of some sort. Since then, I've noticed how true that is. For example, here are the opening words from some of the articles in the Jan. 16 issue:
"Last week,"
"On a dark winter evening"
"In 2011,"
"On a rainy night in late November,"
"In the eighteen-sixties,"
"A few weeks after the fall of President Hosni Mubarak,"
And here are some from the Oct. 11 issue (I just grabbed these two issues at random from the pile on my nightstand):
"Since September 11, 2001,"
"The other day,"
"Over the course of the past four years,"
"When Oliver Stone's 'Wall Street' came out, in 1987,"
"On a warm night during a trip to Beijing last month,"
"Two months before I was to leave Bombay for Toronto,"
"In 1980,"
"On April 20, 2010,"
"In the early nineties,"
"When Marvin Miller took over as the head of the Major League Baseball Players Association, in 1966,"
"In Biafra in 1968,"
"Some years ago,"
Once you become aware of this pattern, it's both amazing and slightly tiresome. It's not just occasional -- literally almost all of the articles excluding the reviews and fiction start out with a time reference. I don't have, say, a Harper's or Atlantic handy for comparison, but I bet they don't do it as often.
Maybe it's a Remnick influence? I don't remember if this was the pattern back in the Brown or Shawn eras.