Which deployed jar contains android.os.SystemClock?

On my device (HTC One M8) android.os.SystemClock is in /system/framework/framework3.jar. I believe framework is separated into multiple jars because of the 65k method limit on classes.dex. android.os.SystemClock may be in a different jar on different android devices.

Steps I used to find where android.os.SystemClock was located:

adb pull /system/framework/<filename>.jar

I then decompiled classes.dex to a jar with DexToJar and viewed the packages inside the jar using JD-GUI (you could just open it as a ZIP file, jd-gui is not necessary and for windows only)