"...and it is my fault it was not posted on the 20th,..."

Though we disagree regarding the question who's is responsible for the situation PTSC is in, I 100% believe what you say.

We're all humans and overlook things which seem to be hidden in the first place and then are so obvious we can't imagine how we could ignore them.
So you absolutely don't have to apologize yourself for this, especially not with this seriousness.

And more important: though it's great you see posting Pacers as your "duty" and therefore characterize this mistake as your "fault" - both is wrong!

We all benefit from your willingness to bring the Pacers to this messaging board (and with that worldwide!) but it's a service and NO duty, hence overlooking a Pacer is not something which you should label as "fault" - it simply happens, eom.

GLTY