Okay, I have added the timezone identifier in the function parentheses. (I really do try to be proactive.) It hasn't made any difference though.
This is the kind of thing that sends me into despair. This morning I had an operating website. Very limited, but it was presentable and, to the extent it existed, it worked.
Tonight, though, that is all behind me. I no longer have an operating site. All I have are a set of pages that have a huge, long, red error notice splashed down every single one.
I've done all the logical things -- I made the change indicated by the error notice. I looked for an "include" file or directory, since that is what the error notice is focused on -- but there isn't one.
Again, this morning I didn't have much, but I had something. Tonight, I've got nothing except a set of ruined pages that I don't have a clue how to fix. 🙁 🙁 🙁