If you're concerned about employees clocking in before they're on site and ready for their shift, you can enable geofencing from your Time Clock settings.
Go to your Time clock settings (Dashboard > Settings > Timeclock).
There, you will find a setting labeled Enable geofencing. Switch the toggle to "Yes" and you will see additional options appear which allow you to choose how you would like Sling to identify employees' locations.
You can choose to have geofencing enforced only at clock-in, only clock-out or both.
Then you can choose from two options to recognize employees' locations:
Connected to location Wi-Fi (IP address) means that employees using a device on an approved network will be able to use the time clock. This could be a mobile phone connected to the location's Wi-Fi or a desktop computer at the location that is connected via ethernet or Wi-Fi. If they are not on an approved connection, they will receive an error.
In order for this setting to work, you must set your IP address(es) in your location settings. Learn more here.
GPS Within specified radius from the location's address lets you define a maximum radius from the work location in which employees can access the time clock. You can define the distance in meters or feet. The minimum you can set is 100 meters or 330 feet.
For this setting to work, you must have a street address entered for your location. Learn more here.
If all else fails or if you have employees whose location may change throughout the day, there is an option to Allow clocking in and out outside of the radius. This will bypass the geofencing restrictions and allow employees to clock in and out - even if they don't match one of the above. These events will be recorded in the employees' timesheets so you can see which employees are not at the location and check for any abuse of priveledges.