Sevenight or Sevennight: How To spell?
The word Sevenight is misspelled against Sevennight, a noun meaning "A week; any period of seven consecutive days and nights. See Sennight."
Sevennight has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings seve & ight which should not be misspelled with single 'N'
Wrong Spelling:  seve-n-ight  Correct Spelling:  seve-nn-ight 
Find more wrongly spelled words of Sevennight to spell it well.