"Everyday"means"每天"inEnglish.Ifyouwanttosay"everynight"inEnglish,youcansay"everyevening,""everynightfall,"orsimply"everynight."
"Every day" means "每天" in English.
If you want to say "every night" in English, you can say "every evening," "every nightfall," or simply "every night."