Relative timestamp when real time clock is unavailable

摘要

An operating system or other software resident on an electronic processing device employs aggregated timestamps. In this way timestamps can be generated and compared to one another without the need for a real-time clock with a power backup. Aggregated time includes the last known time that the device synchronized its clock with a reference time available over a network. Aggregated time also includes a relative time value which in part accumulates using a session clock whenever the device is powered-up. When network time becomes available the operating system or other software will use this information to fix up the already generated aggregated timestamps. A comparison of timestamps will most of the time be resolved for stamps generated on the same device and will generally be resolved by comparing time frames when the timestamps being compared are generated by different devices.

主权项

1. A method for generating a timestamp for an event that occurs on an electronic processing device, comprising:
determining a last available network time when a timestamp was made and a relative time at which the event occurs; generating a first aggregated time value of the event based on the last available network time when a timestamp was made and the relative time at which the event occurs; revising the first aggregated time value when network time is next available to provide a revised aggregated time value; associating the timestamp for the event with the revised aggregated time value; and wherein the relative time at which the event occurs includes a power time that represents a time that begins with a session following the last session in which network time last became unavailable and which accrues over one or more sessions during which the electronic processing device is powered up and which is unset whenever network time is available.