Hi @Jeremiah138
Custom trip lengths have been removed in the update. Existing custom trip lengths remain until they run out, but you can't set new ones.
You now have to click a date on the calendar and select custom setting to set the "minimum nights" for that date. You can select multiple nights at a time if you want to set the same minimum for all of them (for example your 5-night minimum for winter nights).

If you use professional hosting tools, you also have the option of adding trip lengths to your rule sets.