noun
at work; on duty; during work hours
Used to indicate that someone is currently working or that something occurs during work time. Often seen on signs or in formal contexts.
課長はただいま執務中です。
The section chief is currently at work.
執務中は私用電話をご遠慮ください。
Please refrain from personal calls during work hours.
Compound of 執務 (shitsumu, 'performance of duties') + 中 (chū, 'in the middle of').