noun, adverb
on duty; at work; while working
Describes being in the state of working, especially during one's shift or working hours. Often used in rules, announcements, or to describe actions done while on the job.
勤務中は私用電話を控えてください。
Please refrain from personal calls while on duty.
彼は勤務中に事故に遭った。
He had an accident while working.
Compound of 勤務 (duty, work) and 中 (in the middle of, during).