This read-only IetfYangTypesDateAndTime value records when the performance-monitoring counters for a subcard (a daughter module within a larger card) were last cleared, defaulting to the all-zero timestamp. This lets operators scope subcard-level counters correctly, which matters on modular Groove cards where each subcard has its own independent counter set. For example, a technician who swaps a subcard would expect subcardStatisticsEntryLastClear to reset to the swap time, confirming old counter history from the previous module was cleared.