I planted a moon flower vine in a pot and trailed it around a small trellis, it has one huge white bud on it, as far as I know it hasn't bloomed yet, it looks like it's unraveling.

My question is how long do they stay open and what time of the evening do they start to open?Also do they close back up and re-bloom the next evening? I don't want to miss it.

I was surprised how large the bud it. It also has many more baby blossoms to come in the future. Any body have an answer for me?