An apparatus to identify a time shift associated with media presented by a media delivery device , the apparatus comprising: at least one processor; and memory including instructions that, when executed, cause the at least one processor to: generate a library of first signature information local to the media delivery device , the library of first signature information including records, respective ones of the records including a corresponding first time stamp, a corresponding first signature value, and a corresponding first source identifier, respective ones of the records associated with corresponding ones of a plurality of media sources; generate second signature information based on the media presented via the media delivery device , the second signature information including a second time stamp, a second signature value, and a source identifier associated with a first one of the plurality of media sources communicatively coupled to the media delivery device; generate a collection of matching signature information based on a comparison of the first time stamp of the first signature information and the second time stamp of the second signature information; characterized in that the instructions, when executed, cause the at least one processor to: perform a time shift analysis on the collection of matching signature information to identify the time shift associated with the media presented by the media delivery device. at least one processor; and memory including instructions that, when executed, cause the at least one processor to: generate a library of first signature information local to the media delivery device , the library of first signature information including records, respective ones of the records including a corresponding first time stamp, a corresponding first signature value, and a corresponding first source identifier, respective ones of the records associated with corresponding ones of a plurality of media sources; generate second signature information based on the media presented via the media delivery device , the second signature information including a second time stamp, a second signature value, and a source identifier associated with a first one of the plurality of media sources communicatively coupled to the media delivery device; generate a collection of matching signature information based on a comparison of the first time stamp of the first signature information and the second time stamp of the second signature information; generate second signature information based on the media presented via the media delivery device , the second signature information including a second time stamp, a second signature value, and a source identifier associated with a first one of the plurality of media sources communicatively coupled to the media delivery device; generate a collection of matching signature information based on a comparison of the first time stamp of the first signature information and the second time stamp of the second signature information; characterized in that the instructions, when executed, cause the at least one processor to: perform a time shift analysis on the collection of matching signature information to identify the time shift associated with the media presented by the media delivery device. <EOS>