Method and system for improving the accuracy of timing and process accounting within virtual machines

A sponge process, for example within a driver in a guest operating system, is associated in a virtual computer system with each virtual processor in one or more virtual machines. When timer interrupts become backlogged, for example because a virtual machine is temporarily descheduled to allow other virtual machines to run, and upon occurrence of a trigger event, a conventional interrupt is disengaged and catch-up interrupts are instead directed into an appropriate one of the sponge processes. The backlogged timer interrupts are thus delivered without unfairly attributing descheduled time to whatever processes happened to be running while the catch-up interrupts are delivered, and without violating typical guest operating system timing assumptions.