Using Work Time For Personal Endeavors
From Halachipedia
One must be exceedingly careful to maximize one’s work hours only for work-related matters and limit the amount of time dedicated towards personal matters [1]. One must dedicate maximum efforts and strengths towards completing the tasks which one was hired for [2,3]. The performance of one’s job in a faithful manner is exceedingly commendable [4].
Having said that, in modern work environments different employers have different implicit and explicit agreements with their employees regarding work-time allocation (lunch break, taking a walk, checking personal emails, making personal phone calls etc). One should be very stringent to utilize work-time properly, and consider the general practice of the place and time period [5].