Is your client having the Maintenance department with different location & different Time zones??
If yes, you can activate that functionality. Else, it will not have any advantages of activating that.
Even that link suggests
In today's distributed business environments, maintenance no longer takes place at one single location. The most important process steps in plant maintenance, such as planning, execution and confirmation, can be made in different locations, in different systems, with different business partners, and in different time zones.
You can use the time zone support functions to instantly switch from one time zone into another. This is advisable, for example, if you run plant maintenance processes that cross different time zones and you plan plant maintenance activities in a different location to where you perform or confirm plant maintenance activities.
If planning, execution everything happen at single location & time zone, then it will not have any usage.