Is my assessment here correct?
..If 93 nights rolled over from 2016 into 2017, these would earn 2017/2018 platinum, effective the date of roll over in January 2017.
241 total nights in 2017, less 93 rollover (because these only roll over once, yet were used to achieve platinum) so 148 nights roll over into 2018.
Do 93 rollover nights just credit in 2017, but you need to use "new" earned nights in 2017 to earn platinum, so 241 - 93 - 75 = 73 nights roll over?
Of course, this of no consequence into 2019, but I was curious how the rollovers worked for status renewal.