Go ahead, ask Metro when the Silver Line might open. Ask Rob Troup, the transit system’s operations chief — try to pin him down on an estimate.

See if he’ll offer even a potential date — a tentative, possible, don’t-hold-him-to-it, but-if-all-goes-well, then-just-maybe date.

“We absolutely are not putting any undue pressure on ourselves in order to hit an announced date,” Troup said Monday in a conference call with reporters, who asked him, oh, about a half-dozen times, in various ways, when the $2.9 billion first phase of the new rail line might — might — open for passenger service.

Again and again: “Our main consideration … is to ensure that the line is safe for operations, and it’s also going to be reliable.”

Just ballpark it, Rob. How many weeks? “From my perspective,” he said, “I’m not going to put myself in a position where I have to hit a date.”

We know that signs point to August. Metro assumed control of the Silver Line from its builders May 27 to begin testing it, a process that the agency expects will take no more than 90 days. Metro General Manager Richard Sarles and his staff have done nothing to discourage the idea that the line will be operating before Labor Day.

But still. … The contractors have fallen behind schedule with their final “punch list” work. And Metro officials fear that if they mention a tentative date for the opening — no matter how many conditions they attach to it — they’ll be putting themselves under a deadline, which they said could compromise the quality of the project.

“Metro Eyes July 28 Start For Silver Line Passenger Service,” read a headline Monday on the Web site of radio station WMAU. The reporter, Martin Di Caro, wrote that Jackie Jeter, president of Amalgamated Transit Union Local 689, had given him a Silver Line scoop. “We were contacted [by Metro officials] back in May and we were told that simulated service would start July 20,” he quoted Jeter as saying.

Meaning that Silver Line “revenue” service, with passengers, would begin a week later.

On Monday’s conference call, after Troup talked about the contractors lagging with their punch-list work, Di Caro asked him, “How does what you just announced regarding behind-schedule items effect your plans for that July 20th date that you’ve been eying since May?” To which Troup replied, in so many words: What July 20th date?

“We didn’t specify any specific date for that” with the union, Troup said. “It’s simply to-be-determined. … So in that regard, you know, I don’t want to say we’re targeting any specific date. What we are doing is, we’re waiting for our comfort level, for when we can be assured that the punch-list items … are taken care of.”

He said, “What we don’t want to do is have any specific date out there,” because he doesn’t want workers cutting corners to hurry through the punch list, because “that would compromise our ability to be able to initiate safe and reliable service.”

Later in the call, The Post’s Lori Aratani raised her hand telephonically.

“Hi, Rob. I’m going to ask a question that I’m sure you’re tired of. But are we still looking at a summer opening?”

No long sigh from Troup, no hint of frustration, just: “Right now, again, I caveat that statement that we are moving with as much alacrity as we can on this. But personally, I am not going to put myself in a position where I need to put any undue pressure on making the system [function] right. So we are doing everything we can to get the service out there as quickly and as efficiently as possible.”

He did say that Sarles on Thursday will ask Metro’s board of directors to give him the authority to set an opening date.

“I want to be specific,” Troup said, “that this board action will not set the actual date for opening. It will only delegate the authority to the general manager to make a decision on the opening date.”

And don’t bother asking when that might be.