The VIP icon appears in the upper left of the screen, next to the commander. If it is active, it will appear in full color. If not, it appears gray.
VIP has ten ranks at this time. Each rank provides more benefits to the city. For example, the length of time required for constructing a building is reduced as the VIP rank increases. The ability to field an additional army is a benefit at rank 8.
VIP points can be obtained through combat with zombies in the local area view. They are also awarded for completing certain activities. The points can also be purchased with diamonds. As the points accumulate, your VIP rank increases.
The effects of VIP rank are limited in time. The most common way to obtain time for VIP is to complete one of the levels in an activity. Reaching the first waypoint of an activity will result in you receiving a message containing the reward for that success. A one day extension for VIP can be one of those rewards.
VIP time can also be bought with diamonds.