We’ve now had two congressional hearings devoted to figuring out just what happened with the response to the Jan. 6 Capitol riot. In both, a key discrepancy emerged in the timeline when it comes to the deployment of the National Guard.

Last week, it was between the former Capitol Police chief Steven Sund and former House sergeant-at-arms Paul Irving over when Sund first requested the Guard.

On Wednesday, it was between the commanding general of the National Guard and the Defense Department over when the Guard was actually given its approval to go into the Capitol.

“How is that possible?” Sen. Roy Blunt (R-Mo.) said Wednesday. It’s a good question — and one that reinforces how inexplicable and irreconcilable some of the conflicting versions of Jan. 6 remain, nearly two months later.

Here’s what we know about the timelines and what’s disputed.

The initial request: Around 1 p.m. vs. after 2 p.m.

Security officials disagreed on Feb. 23 over what time a request was made for support from the National Guard during the Jan. 6 attack on the Capitol. (The Washington Post)

Sund said in his testimony last week that he initially requested the National Guard in a phone call with Irving at 1:09 p.m., and that he called to check on it shortly thereafter. Irving, though, said he didn’t receive such a request from Sund until after 2 p.m.

While that discrepancy has gotten the attention, though, neither claim lined up with testimony of acting Capitol Police chief Yogananda Pittman later in the week.

Sund said in his Feb. 23 testimony that he made his first request of Irving at 1:09 and then followed up at 1:22 p.m.:

1:09 p.m.: “It was 1:09,” Sund said, adding that the request for assistance “was from Mr. Irving. I believe he was in the company of [then-Senate Sergeant-at-Arms Michael] Stenger at time as well.”

1:22 p.m.: “I followed up at 1:22 to check on the status of the request.”

Irving, though, said he didn’t receive a request until after 2 p.m. He said they did speak earlier — though he had no recollection or record of speaking before 1:28 p.m. — but that Sund even then didn’t make such a direct request.

Here’s Irving’s timeline:

1:28 p.m. or 1:30 p.m.: Irving says he had his “first conversation” with Sund, and that Sund mentions the possibility of needing the National Guard — but doesn’t request it. “In that conversation, he indicated that conditions were deteriorating, he might be looking to — for National Guard approval … and I went Mike Stenger’s office awaiting an update.”

Shortly after 2 p.m.: “I did not receive a request for approval for National Guard until shortly after 2 p.m. when I was in Michael Stenger’s office.”

Neither version lined up with Pittman’s testimony on Feb. 25. Pittman said she checked phone records and found the first request actually came earlier than Sund testified. Here’s what she said happened:

12:58 p.m.: Sund “first reached out for National Guard support to the House sergeant-at-arms,” Irving. (She said he made the same request to Senate Sergeant-at-Arms Stenger shortly afterward, at 1:05 p.m.)

1:28 p.m.: Sund repeats his request to Irving.

1:34 p.m., 1:39 p.m. and 1:45 p.m.: Sund again speaks with the sergeants-at-arms “to request National Guard support.”

So depending upon whom you believe, the first request Sund made to Irving came at 12:58 p.m., 1:09 p.m. or shortly after 2 p.m. What’s more, Pittman suggested separate initial requests of each sergeant-at-arms, but Sund indicated he felt he was speaking to both of them at the same time. And Sund pegged a follow-up call at 1:22 p.m., which is both before Irving says they first spoke and before Pittman’s call records indicate the first follow-up came.

About all that is generally agreed upon between the accounts is that there was some kind of conversation between Sund and Irving shortly before 1:30 p.m., but even then, the content and the exact timing differs.

Irving’s testimony is bolstered somewhat by video showing him on the House floor, as he testified, at 1:09 p.m., as Politico reported and The Fix’s J.M. Rieger clipped — though it doesn’t definitely show he never received or took a phone call at that time.

The New York Times has also reported that Irving approached House Speaker Nancy Pelosi’s (D-Calif.) staff about the National Guard at about 1:40 p.m. -- the first time, according to Pelosi’s office, that he sought permission from her. After speaking with her chief of staff, video then shows the chief of staff approaching Pelosi at 1:43 p.m., at which point Pelosi gave permission.

That doesn’t necessarily confirm or disprove anybody’s timeline, but it suggests Irving was pursing these options even before he said Sund made the request. And the existence of the video footage -- this was off the House floor -- suggests there could be additional such evidence that might shed light.

When the Guard was actually sent in: 4:32 p.m. or 5:08 p.m.

On March 3, commanding general of the D.C. National Guard Maj. Gen. William J. Walker discussed how his request to mobilize against the Capitol mob was delayed. (Blair Guild/The Washington Post)

This one came at Wednesday’s hearing. The commanding officer of the D.C. National Guard, Maj. Gen. William J. Walker, testified that the approval for Sund’s request for the Guard wasn’t received from the Defense Department until 5:08 p.m. — hours after Sund initially made it.

But the representative for the Defense Department, Robert Salesses, initially testified that the Guard was told it could move forward at 4:32 p.m., before seeming to walk that back a bit.

Here’s Walker’s version:

5:08 p.m.: “The approval for Chief Sund’s request would eventually come from the acting secretary of defense [Christopher Miller] and be relayed to me by Army senior leaders at 5:08 p.m., about three hours and 19 minutes later.”

5:20 p.m.: The National Guard arrives at the Capitol and is sworn in.

And here’s the version from Salesses, the Defense Department official:

Approximately 2:30 p.m.: Miller determines that “all available forces of the D.C. National Guard were required.”

3:04 p.m.: Miller orders the “full mobilization” of the Guard.

4:32 p.m.: “The secretary of the Army received the acting secretary of defense’s approval at 4:32 p.m. and ordered the D.C. National Guard forces to depart the armory for the Capitol Complex.” Salesses says this is also the moment at which the Guard was told it could move forward.

This discrepancy, unlike its predecessor a week before, actually got drilled down on. Blunt tried to reconcile the versions between Walker and Salesses, at which point Salesses seemed to qualify his timeline.

When Blunt asked Walker about Salesses’s claim that the Guard was told it would move forward at 4:32 p.m., Walker responded directly, “No, sir.”

“I didn’t get approval until a little bit after 5, and I got that from the secretary of the Army who was relayed to me,” Walker said, adding: “Army senior leaders told me, at about 17:08, 5:08 p.m., that the [acting] secretary of Defense has authorized our approval to support the Capitol.”

At this point, Salesses allowed that perhaps the message hadn’t actually been conveyed to Walker immediately upon the 4:32 p.m. approval.

“In fairness to Gen. Walker, too, that’s when the [acting] secretary of defense made the decision — at 4:32,” Salesses said. “As General Walker has pointed out, because I’ve seen all the timelines, he was not told that until 5:08.”

Just moments prior, though, Blunt had asked Salesses whether 4:32 p.m. was “the moment when the Guard was told they could move forward,” and he responded, “Yes, senator, it is.” That strongly suggests this was actually conveyed to the Guard at that time.

When Walker disputed it, though, Salesses suggested there might indeed have been some kind of lag between the approval and the Guard actually being informed.

“Senator, I think — I think that’s an issue,” Salesses said. “There was decisions that were being made, there was communications that needed to take place, and then there was actions that had to be taken. All of that was happening at simultaneous times by different individuals, and I think that part of the challenge is that some of the delayed communications probably” complicated the response.\Salesses, in his own testimony, acknowledged he wasn’t directly involved in many of the key events that day, and the Defense Department declined to send someone more senior to answer questions. Having someone who could actually speak to these issues more authoritatively might have been a good idea, given Salesses’s own testimony didn’t seem to be terribly consistent.

But even if he merely slipped up and this did just owe to some kind of lag in actually informing the Guard, how on earth could that happen? How could the Guard be approved at 4:32 p.m. but its commanding general not get word until 5:08 p.m., even as the Capitol was under siege? It just makes no sense.

And as with the first example, the fact that this discrepancy still exists two months later might be the most inexplicable thing of all.