30.666 it is.

As long as it allows for 2 night spawns, assuming timing and luck.
Albeit less time than 30.5, but its still possible.

Back to back spawns will be extremely rare now.
Earlier in the year I was aware of 4 rings in 5 hours, back to back twice, with 2 hours inbetween.
Another time it was 4 rings in 6 hours.