Need a clock in Numbers
I want to use Numbers on my iMac (macOS) to display a running clock which I will use for a chess timer. However the NOW function (which is one way to get the time) doesn't actually update on a continuing basis. It seems to require manual editing to update the time. Are there any other Apple products that I might be able to achieve this with? Maybe Pages? Maybe Keynote? Maybe Automator? I've got this sinking feeling that all Apple's products won't deal with clocks or other real time events but are designed to work only with static files. Do I really have to learn how to use Xcode just to display a clock?
iMac (Retina 5K, 27-inch, Late 2014), OS X Yosemite (10.10.4)