There are "nocturals" which sometimes open in the evening and will stay open longer than 24 hours. Last fall ( during extremely cool weather ) I noticed that some blooms were staying open for two days. Those who live in cooler climates, especially if the weather stays cool for extended periods during bloom season, might notice that the blooms stay open for longer than one day. But we call them "Hemerocallis" for a reason - the translation means "beauty for a day"!