All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Fraud and falsification are forbidden in all situations, and it isn`t permissible for an employee, whether in in charge of others or not, to manipulate dates to cheat the system. This is because the Messenger of Allah (PBUH) says: "……He who deceives has nothing to do with me." {Related by Muslim, pp.295}.
Instead of committing forgery, it is better to level with the official in charge and clarify the situation for him and accordingly he may have the power to override the system since this is better than committing the above violation which may lead to great evils, such as eating up people`s wealth unjustly and impairing the rights of others.
Accordingly, we advise this person to make sincere repentance, ask Allah for forgiveness and do his best to set the records straight as much as he can. And Allah the Almighty Knows Best.