Method, apparatus and system embodiments are disclosed for one or more programmable registers to hold wakeup time values for power management. For at least one embodiment, information based on the values in the programmable registers may be utilized by a power management unit to determine whether a power island has had sufficient time to transition out of a low power state. The values of the programmable registers may be dynamically modified during operation of a processing system. Other embodiments are also described and claimed.