Utilities questions if tenants have not moved in yet

[Steve Tom]

Hello.

After fixing up the house, my realtor was able to find a couple as prospect tenants. They want to move in early September, and are willing to pay for the August's rent even if they won't be at the house. 

The question is who is responsible for the utilities for the month of August? I don't mind mowing or paying for the utilities, just to be a little fair since they are not living at the property yet.

Thank!