MARC THIESSEN IN THE WASHINGTON POST: Where was Obama during Benghazi? Ask the White House diarist.

What was President Obama doing during the eight hours that the U.S. diplomatic compound in Benghazi, Libya, was under attack? Amazingly, we still do not know 20 months later.

But there is an easy way to find out — just ask the White House diarist. When trying to keep track of the president’s time, most observers look at “WAVE records” (the White House visitors log listing everyone who enters the White House complex) and the “President’s Public Schedule” (which selectively lists the president’s public activities). But there is another document that meticulously records all the president’s activities, public and private, every second of every day. It is called the “President’s Daily Diary.”

Just outside the Oval Office is a room called the Outer Oval, where the president’s secretary and personal aide sit and through which all visitors coming to see the president pass. Staff members in the Outer Oval keep track of the president’s location at all times. They carefully record the names of all individuals who walk into the Oval Office — when they entered, how long they stayed, what the topic of discussion was. They keep a record of all calls made and received by the president, including the topic, participants and duration. They even record the president’s bathroom breaks (they write “evacuating” into the log).

Congress could also subpoena his Secret Service detail. Plus: “During Watergate, Richard Nixon had his infamous 18 1 / 2-minute gap. When it comes to Benghazi, Obama has an eight-hour gap. That gap needs to be closed. If Obama has nothing to hide, then he has nothing to fear.” Obviously he has something to hide, or he wouldn’t have hidden it for 20 months.