I was partway through writing this post when I decided to retest on the most recent master from github, and that seems to have fixed it. (Then again, the problem comes and goes, so maybe not...) But in case somebody else is having this problem, or the sample code is otherwise useful, here's the orig...

That's the point. There's an SNTP library already in the ESP-IDF, as part of lwIP. In the example linked above, initialize_sntp shows the calls to the library.

I've been using the ESP32 for a little over a month now, and never could get into the ROM BASIC. Now that I read https://www.esp32.com/viewtopic.php?t=2799 and https://github.com/espressif/esp-idf/releases/tag/v3.0-rc1, I see why. I let the first boot irreversibly disable ROM BASIC. I've got other d...