Old habits are hard to break.  Just ask Matt Lauer.

It was a long work day for the morning show veteran, who filled in tonight on Nightly News for the first time in ten years.  Known for his usually near-seamless anchoring, Lauer this evening waged a very human battle with his dayside-nightside references.

It all started when NBC’s chief legal correspondent wrapped up her analysis of the John Edwards trial.  Lauer thanked “Savannah Guthrie, in the studio this morning”.

After a commercial break, Lauer clearly was cognizant of the mix-up. Tossing to correspondent Ron Mott, Lauer said, “Good evening, Ron” – with a heavy emphasis on ‘evening’.

But when Mott completed his live tag and tossed back to the studio, Lauer thanked him for reporting from New York “this morning”.

The rest of the newscast then was smooth sailing…until the closing moments.

“And that’s our broadcast for this Thursday night, thanks for being with us. I’m Matt Lauer in for Brian tonight, and I’ll see you tomorrow morning on Tonight. On Today, excuse me!” he said while laughing.

Update: Checking the KUSA-TV/Denver feed, the Guthrie “morning” reference stayed in…as did the one with Mott. Lauer was able to re-do his farewell, though, telling viewers he’ll see them “tomorrow morning on Today“.