over 4 years ago - Shurenai - Direct link
An important set of questions for each of the people having the issue.

One, Did you at any time during the latest 7 days alter the Blood Moon Frequency or Blood Moon Range settings? Changing either one to a different value and loading in will cause the game to re-calculate the next blood moon from the current day- This includes setting it to 'Disabled' and later changing it back.

Two, Did either of you fiddle around with the Debug Mode's Time slider, and/or the set time command? Messing with the game time without knowing exactly what you're doing can very easily break blood moon timing in your save- Thankfully it is usually salvagable by doing what question one says; Setting the value to some other value in order to force the game to re-calculate the blood moon time.