Double Time is an ability for the Engineer in Plants vs. Zombies: Battle for Neighborville. When activated, Engineer deploys a pad that boosts allies' speed when they walk through it. Only one Double Time per Engineer can exist at a time.
Longer duration of Double Time speed boost.
Increases Double Time speed boost duration by 1 second (to 3.5 seconds).
Rally the Troops
Faster refresh time on all abilities when allies use Double Time.
Reduces ally ability cooldown by 2 seconds upon using Double Time. This effect has a 2-second cooldown between each activation.
Similar to Arcane Enigma, a Double Time's main use is for boosting the speed of yourself and your allies. Placing one where everyone can see it will help your team greatly, especially in matches of Turf Takeover where you need to travel large distances to get to objectives. Just make sure that it isn't too visible, otherwise the plants will see it and destroy it, forcing you to have to wait a few seconds before placing another one.
Don't be greedy and place down a Double Time whenever you have one available just because you want a short speed boost. The Engineer is a Support class, and as such he needs to be able to support his allies, not just help himself.
Because you usually don't look down when playing as the plants team, as there usually isn't anything there to harm you, you could walk right over a Double Time without even knowing it. If you happen to come across one, it's recommended to destroy it as quickly as possible to ensure that it can't be used again for a while.