1# Simple Clock 2 3### Introduction 4 5This sample exemplifies how to implement a simple clock application using the eTS UI capability. 6 7### Usage 8 9The UI uses **setInterval** to update the time at regular intervals and uses **Canvas** to draw the clock, where the rotation angles of the clock hands are obtained through calculation. 10 11For example, **2 * Math.PI / 60 * second** indicates the rotation angle of the second hand. 12 13### Constraints 14 151. This sample can only be run on standard-system devices. 16 172. This sample demonstrates the stage model, which supports only API version 9. 18 193. The DevEco Studio version used in this sample must be 3.0.0.900 or later. 20