After my 4th e-mail from Delta I got an interesting answer. Add this information to what Bensky13 wrote, and here is the answer I have.
Dedicated Pre-check Line Time at Laguardia C & D
Sunday–Friday 5:00 AM–8:00 PM,
Saturday 5:00 AM–6:00 PM
Precheck Lite at Laguardia C & D(What it might be is that you get a card and are allowed to walk through the metal detector but have to wait in regular security line).
Sunday–Friday 4-5am & 8-10pm
Saturday 4-5am & 6-8:30pm
Pro-Tip: If you have a bit extra time people suggest going through Terminal D even if you flight leaves from Terminal C.
Original Sources below:
Originally Posted by
Bensky13
I occasionally fly out of LGA Terminal C ~9:30PM on Sundays, and I've never seen dedicated PreCheck open at that time. I asked once when they close it, and was told 8PM. They'll give you the flimsy paper sheet that grants you "PreCheck lite"
Of course, at that time there aren't that many flights, so I've never had more than a few minute wait at security.
Message from Delta.
"We recommend you arrive at the airport 75 minutes prior to departure for
travel within the U.S. at LaGuardia. Hours of operation is 0400 to 2200
hours Sunday through Friday and 0400 to 2030 hours on Saturday."