The ornamental design for a targetclock, as shown and described.
FIG. 1 is a front and right side perspective view of a target clock showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken lines showing the time on the display in FIGS. 1 and 2 and the broken lines showing the buttons on the top of the clock in FIGS. 1 through 5 are for illustrative purposes only and form no part of the claimed design.