The ornamental design for a powersockettimer, is as shown and described.
FIG. 1 is a front right perspective view of a power socket timer showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The structural features depicted by broken lines in the figures have been shown for the purpose of illustrating portions of the power socket timer that form no part of the claimed design.