With Guardian Keypads, the keypad does not determine how long to hold the gate open only how long to send the open command. Think of this like having a gate remote. When you press the button the light turns on and stays on until you release the button. Once the button is released, the time the gate takes to close is completely dependent on a timer within the gate motor itself.
To adjust the amount of time the keypads send the open command to the gate go to the variables tab in Guardian Control Panel. Shown in red below is the gate relay time in seconds. 5 is the default value but this can be increased or decreased as needed.
Door Strikes: Door strikes are one reason a site may need to increase relay time. Tenants may need the door strike to unlock a door for longer than 5 seconds to enable them time to get from the keypad to the door. In that case the relay time can be increased as needed but keep in mind this is a global setting. If the gate relay time is increased to 10 seconds that will apply to all keypads.