Q: My employer wants me to exagerate the time spent on tasks on a timesheet for a client.
الجواب حامدا ومصليا ومسلما ومنه الصدق والصواب
A: You cannot make a dishonest claim even if it is at the insistence of your employer.
If it is normal practice that the time taken to register the time in the time sheet is included in the time spent on the project then it permissible for you to book such time for the project. However, if it is not the industry/sector norm then you must either not include it in the time spent on the project or else secure the permission of the client to do so.