If I have a salaried exempt manager who takes 3/4 of a day off to go to a baseball game can I just deduct some of his salary to offset the time he didn't work?

Not without ruining his status as an exempt employee.  As a general rule, exempt employees are entitled to their weekly salary in any week in which they perform work, but there are exceptions. One of the exceptions occurs when an employee takes more than a full day off for personal reasons. Federal law allows companies to deduct in full day increments from an exempt employee's salary for time the employee takes off for personal reasons. So, in this situation, because the employee took less than a full day off to go to the baseball game, a partial day deduction would not be appropriate.

 
 
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