I took this pictures at around 10:00 PM ;)

This is the Dragon Fruit Cactus Flower (Hylocereus undatus) also known as Pitahaya or Pitaya.

. This lovely flower is nocturnal and only lasts for one day, I've been waiting for this moment like "forever" to take some pictures.
The flower bud will undergo a dramatic growth boom a few days before it opens.
On that day when the flower opens, the flower bud will pucker and reveals a tiny amount of its white petals at the end. The flowers will wait for the sun to vanish before it actually start to open.
The flower springs into action at the moment the sun no longer directly shines on the plant.
The flowers can be seen the following morning but for only a short period of time. The lovely flowers are short lived and will be wilted by the following day.

Here is a time-lapse photography of a Dragon Fruit Flower:

The Dragon Fruit when ready for harvest turns very plump, brightly colored and "scales" are erect.