A system and corresponding method virtualizes a real-time clock in the presence of a time-disrupting event. The real-time clock is used with physical machines and includes a single time source within each of the physical machines. The system is implemented in one or more programmable devices, which may be hardware and/or software devices, or a combination of hardware and software devices. The physical machines include one or more virtual machines. The system includes an offset module that determines a time difference offset between a virtual interrupt timer counter (ITCV) associated with a virtual machine and a physical interrupt timer counter (ITCP) associated with a physical machine. The system also includes a virtual machine monitor that computes one or more first time adjustments based on the offset and applies the adjustments to eliminate at least a first part of the offset.