Time based content management for disconnected devices

Abstract

Systems and methods for time based management of digital content used with electronic devices lacking a connection to a common reference time keeping device are provided. Timing calibrations are used that, when applied to times measured by such disconnected electronic devices, allow the devices to calculate modified time measurements that are approximately equal to that of the reference time keeping device. The calibration time and other calibration information for the disconnected electronic devices may be stored by a digital content service and conveyed with digital content transferred from the digital content service to the disconnected electronic devices via portable data storage devices. In this manner, digital content may be consumed by a user on a plurality of disconnected electronic devices without violating license agreements associated with the digital content.

What is claimed is: 
     
         1 . A computer-readable medium having a computer-executable component for synchronizing time keeping, the computer-executable component comprising:
 a time calibration component operative to:
 retrieve a first reference time according to a reference time keeping device in response to a time calibration request for a disconnected electronic device; 
 request a device time maintained by the disconnected electronic device, wherein the request is delivered by a portable data transfer device; 
 retrieve a second reference time according to the reference time keeping device; and 
 determine a time calibration value for the disconnected electronic device comprising a function of the first reference time, the second reference time, and the device time. 
   
     
     
         2 . The computer-readable medium of  claim 1 , wherein the time calibration component is further operative to provide the time calibration value to the disconnected electronic device via the portable data transfer device. 
     
     
         3 . The computer-readable medium of  claim 1 , wherein the time calibration request comprises a request from a user. 
     
     
         4 . The computer-readable medium of  claim 1 , wherein the disconnected electronic device enables a user of the disconnected electronic device to consume digital content. 
     
     
         5 . The computer-readable medium of  claim 4 , wherein the digital content comprises at least one of text, audio, video, and software applications. 
     
     
         6 . The computer-readable medium of  claim 1 , wherein the reference time keeping device comprises a network resource. 
     
     
         7 . The computer-readable medium of  claim 1 , wherein the reference time keeping device comprises a network accessible server that executes the time calibration component. 
     
     
         8 . The computer-readable medium of  claim 1 , wherein the portable data transfer device comprises at least one of universal serial bus (USB) memory devices, flash memory devices, magnetic media, and optical discs. 
     
     
         9 . The computer-readable medium of  claim 2 , wherein the disconnected electronic device is capable of using the time calibration value for synchronization with the reference time keeping device. 
     
     
         10 . The computer-readable medium of  claim 1 , wherein the time calibration value comprises the sum of a device time correction and a synchronization time correction calculated according to:
   device time correction=first reference time−device time
     synchronization time correction=first reference time−second reference time
   
     
     
         11 . A computer-readable medium having a computer-executable component for restricting access to digital content, the computer-executable component comprising:
 a license enforcement component configured for integration with an electronic device that enables access to digital content and is not in communication with a reference time keeping device, wherein the license enforcement component is operative to:
 identify a first time at which a request for access to a digital content is made, the first time measured according to a time keeping device maintained by the electronic device; 
 identify a time period during which the electronic device is permitted to access the digital content, the time period measured with respect to the reference time keeping device; 
 obtain a time calibration value for the electronic device from a portable data transfer device that is capable of transferring information from the reference time keeping device and the electronic device; 
 determine a second time representing the time at which the request was made with respect to the reference time keeping device by modifying the first time with the time calibration value; and 
 permit the electronic device to access the digital content if the second time is within the identified time period. 
   
     
     
         12 . The computer-readable medium of  claim 11 , wherein the license enforcement component is further operative to obtain a first authentication number maintained by the electronic device that is changed when the time keeping device maintained by the electronic device is reset. 
     
     
         13 . The computer-readable medium of  claim 12 , wherein the license enforcement component is further operative to deny access to the digital content if the first authentication number and a second authentication number obtained from the portable data transfer device for the time calibration value are not equal. 
     
     
         14 . The computer-readable medium of  claim 11 , wherein the digital content comprises at least one of text, audio, video, and software applications. 
     
     
         15 . The computer-readable medium of  claim 11 , wherein the digital content is transferred to the portable data transfer device for delivery to the electronic device. 
     
     
         16 . The computer-readable medium of  claim 15 , wherein the time period comprises at least one of:
 a time period that begins upon first access permitted to the digital content;   a time period that is specified by fixed dates; and   a time period that begins upon transfer of the digital content to the portable data transfer device.   
     
     
         17 . The computer-readable medium of  claim 11 , wherein the time calibration value comprises a sum of:
 a difference between a first time measurement according to the reference time keeping device and a second time measurement according to the electronic device.   an amount of time required to obtain the second time measurement from the first time measurement, as measured with respect to the reference time keeping device.   
     
     
         18 . The computer-readable medium of  claim 11 , wherein the time calibration value is generated by a manufacturer of the electronic device. 
     
     
         19 . A system for synchronization between electronic devices, comprising:
 a data store that stores time data; and   a time calibration component in communication with the data store, the time calibration component operative to:
 in response to a time calibration request for a disconnected electronic device, retrieve a first reference time according to a reference time keeping device and store the first reference time in the data store; 
 request a device time maintained by the disconnected electronic device, wherein the request is delivered by a portable data transfer device and is stored in the data store upon receipt; 
 retrieve a second reference time according to the reference time keeping device and store the second reference time in the data store; and 
 determine a time calibration value for the disconnected electronic device comprising a function of the stored first reference time, second reference time, and the device time. 
   
     
     
         20 . The system of  claim 19 , wherein the time calibration component is further operative to provide the time calibration value to the disconnected electronic device via the portable data transfer device. 
     
     
         21 . The computer-readable medium of  claim 19 , wherein the disconnected electronic device enables a user of the disconnected electronic device to consume digital content. 
     
     
         22 . The computer-readable medium of  claim 19 , wherein the reference time keeping device comprises a network resource. 
     
     
         23 . The computer-readable medium of  claim 19 , wherein the reference time keeping device comprises a network accessible server that executes the time calibration component. 
     
     
         24 . The computer-readable medium of  claim 20 , wherein the disconnected electronic device is capable of using the time calibration value for synchronization with the reference time keeping device. 
     
     
         25 . A computer-implemented for synchronization, the method comprising:
 under control of one or more configured computer systems:
 retrieving a first reference time according to a reference time keeping device in response to a time calibration request for a disconnected electronic device; 
 requesting a device time maintained by the disconnected electronic device, wherein the request is delivered by a portable data transfer device; 
 retrieving a second reference time according to the reference time keeping device; and 
 determining a time calibration value for the disconnected electronic device comprising a function of the first reference time, the second reference time, and the device time. 
   
     
     
         26 . The computer-implemented method of  claim 25 , wherein the time calibration component is further operative to provide the time calibration value to the disconnected electronic device via the portable data transfer device. 
     
     
         27 . The computer-implemented method of  claim 25 , wherein the electronic device enables a user of the electronic device to consume digital content. 
     
     
         28 . The computer-implemented method of  claim 25 , wherein the reference time keeping device comprises a network resource. 
     
     
         29 . The computer-implemented method of  claim 25 , wherein the reference time keeping device comprises a network accessible server that executes the time calibration component. 
     
     
         30 . The computer-implemented method of  claim 26 , wherein the disconnected electronic device is capable of using the time calibration value for synchronization with the reference time keeping device.