宵っぱり
Noun
1
noun (common) (futsuumeishi)
night owl;nighthawk;late bird
私もそうだが、ＩＴ業界には宵っ張りの人が多いに違いない。
I'm one too, and I'm sure there are lots of night-owls in the IT world.
2
noun or participle which takes the aux. verb suru
to stay up late;to keep late hours
Other forms
宵っ張り 【よいっぱり】