The boss lets them record a half day as a full day
Question

I am an employee working in a private company. During Eid there is an optional holiday and it is up to the employee if he wants to work during Eid, and that will count as overtime, or he can take five days off as an official holiday. I chose to work, and on the first day my immediate boss told me: I am going to divide the people into two groups, some who will come at the beginning of the day and finish at midday, and others who will come at midday and work until the end of the day, so instead of eight hours our workday was now four hours. That was because there was no work for us, or only light work, or the people who were there would finish the work by the time we came. But basically eight hours would be counted for us, even though we were only doing four hours. All of the employees in the company were doing it that way, after consulting the immediate boss and the one above him, and he agreed to that. What is the ruling on that?.
Praise be to Allah.If what you mentioned happened with the agreement of the immediate boss and his superior, because there was not much work that would require you to put in full hours, and they had the authority to set the hours of work, then there is nothing wrong with that. 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked about a man who sought permission from his immediate boss to be absent from work, and he gave him permission. What is the ruling on his salary? 
He replied: 
If you asked permission from him (i.e., your immediate boss) and you know that the work needs you to be present, then you should not accept this permission, and you have to be present at work even if you are given permission to be absent. But if the work does not need you and your immediate boss gives you permission, then I hope that there is nothing wrong with that. End quote. 
Al-Bab al-Maftooh (14/question no. 17). 
A similar answer was given by Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him). We have quoted his fatwa in the answer to question no. 85055. 
And Allah knows best.