I recently returned a car about 5 minutes late, which I know is bad behavior. However, my invoice reported that I was actually 14 minutes late, so all that last-minute rushing I did was actually doomed from the start. Has this happened to anyone else?

Apparently, the clock in the car doesn't necessarily coincide with the "Zipcar clock," because customers can change it at will. Considering that 3 or 4 minutes difference here or there can lead to a big late penalty, it seems that something should be done to provide accurate time to the Zipcar drivers. Can the car clock be hooked up through the magic swipe system to reflect the Zipcar time? At the least, provide a little warning in the car near the clock: "Don't Change the Clock." Or is there some other way of letting folks know that changing the clock is bad and doesn't actually change time?

-- Anonymous, December 20, 2003

Answers

Since anyone can set the car clocks at any time, they aren't always reliable, though our fleet maintenance people do check them.

Our computers in the cars keep their own accurate time, set to a clock on the server which is set to an accurate time source. This results in accurate tracking of vehicle use.

No, Jonathan, there is no polling.

-- Anonymous, December 24, 2003

Zipcar time is synchronized to an atomic clock, e.g. www.time.gov We don't display the time anywhere, but we'll look into it.

-- Anonymous, December 29, 2003

As I understand it, the Zipcar network is not a real-time system, and so its polling of the presence or absence of a car will only reflect whether a car is back on time or not, as opposed to doing so with minute by minute accuracy. The clock on the dashboard is not connected to the Zipcar hardware, so it does not matter what time it reads. All Zipcar timing is done through the central timebase, which is kept accurately. My best guess is that the Zipcar network polled the car just before you swiped your card to lock it, and so it was not registered as returned on time. It was later polled 9 minutes later, and so recorded as 14 minutes late on the network. These are all just guesses on the part of a network experienced Zipcar member of 3 years. I assume that if I am wrong, that a Zipcar person will correct me.

-- Anonymous, December 24, 2003

So is there a way of checking the "Zipcar time" through the website or the phone system, if it's not displayed in the car itself?

-- Anonymous, December 29, 2003

Aha! My cellphone also displays the time, synchronized to a time standard. So it ought to agree with the Zipcar system's clock, I guess. Never mind...

-- Anonymous, January 01, 2004

Perhaps Zipcar could install a self-setting clock in each car, and duct-tape over the factory clock. See http://atomicwatchesusa.com/ .

NB: These so-called "atomic" clocks reference the same timebase as zipcar's GPS system (though the time gets to the clock a totally different way). A company I worked with used this with great results in public transit buses. No more drivers saying their watch was slow (or fast).

-- Anonymous, January 31, 2004

I am sorry but all this talk about getting the Zipcar time to show in the car seems like a bad idea to me. Why spend the money to desplay this time in the car. As was mentioned earlyer most cell phones have the time from a server and if you are cutting the time that close anyway you should pad your reservation by a half-hour. Just my two cents but I think common sence can save us all some money.

-- Anonymous, January 31, 2004