Wasei-eigo from English 'off time'. Refers to personal free time away from work or duties, similar to 休み or 自由時間 but with a slightly trendy, casual feel.
wasei-eigo (Japanese-coined English), from off time
See also: オンタイム
I enjoy cooking as a hobby in my free time.
It's my first day off in a while, so I think I'll relax and watch a movie.
Wasei-eigo derived from English 'off time'. It is wasei, indicating it was coined in Japan rather than borrowed directly from English usage.