This is correct.AFAIK Danger Limit does nothing if you do not activate Danger Days manually.
If you just enable Danger Days, then danger content with increasing severity will gradually be enabled over a few weeks of ingame time.
If you enable Danger Days and disable Danger Limit, all danger content will be activated immediately.
Days is the on/off switch that enables the danger stuff. Defaults to off, ie no danger, regardless of what the other one says.
Limit controls whether there is a gradual buildup, giving Sammy a chance to work on her stats, or if danger goes straight to max immediately. Defaults to on, ie gradual buildup (over 40 days I believe, but have not actually checked the code to verify).