The ornamental design for a time piece face, as shown and described.
The intended use of the article is as a time piece face having no hands to indicate time of day, but instead displaying time by way of color or light emission viewed from areas of the time piece face shown as circles and rectangles on the accompanying drawing.
FIG. 1 is a frontal view of the time piece face thereof.
The broken lines depicting numerals is for illustrative purposes only and forms no part of the claimed design.
The outer circular broken line in FIG. 1 denotes the nature and environmental use of the claimed design and forms no part of the claimed design.