The ornamental design for a watertimer, as shown and described.
FIG. 1 is a perspective view of a water timer showing our new design;
FIG. 2 is a right side elevational view showing the design for the water timer of FIG. 1;
FIG. 3 is left side elevational view showing the design for the water timer of FIG. 1;
FIG. 4 is a front elevational view showing the design for the water timer of FIG. 1;
FIG. 5 is a rear elevational view showing the design for the water timer of FIG. 1;
FIG. 6 is a top elevational view showing the design for the water timer of FIG. 1; and,
FIG. 7 is a bottom elevational view showing the design for the water timer of FIG. 1.
The structural elements depicted by broken lines in the drawings have been shown for the purpose of illustrating portions of the water timer that form no part of the claimed design.