As of now, 48 hours in a week are the working hours. If it is a 6 day week, every day 8 hours working. If it is a 5 day week, the working hours are nine and half hours. If it is to be made 4 day week without any loss in working hours per week, one has to work for 12 hours every day in all the 4 working days. Is it not very difficult? Can we concentrate on work if we are there in the office for 12 hours? Once in a while staying for additional hours is something different. But all the working days are for 12 hours work means. the employee will get extra strained and he may not be able to give a good output.
There should be a reduction in the overall working hours per week. Then only we can welcome 4 days a week. Otherwise, employees may not be able to work continuously. If there is no change in the total working hours, I never prefer a 4 day week.