1. A method for estimating an image capture date of a photo, comprising: identifying, by a processor, image characteristics of an undated photo; comparing, by the processor, the image characteristics of the undated photo to image characteristics relating to a plurality of reference photos, each of the plurality of reference photos having an established date, wherein the compared image characteristics comprise graininess and wherein graininess is represented by frequency domain data; estimating, by the processor, an image capture date of the undated photo based on a similarity of the image characteristics of the undated photo to one or more of the image characteristics of the reference photos; displaying at a user interface, by the processor, the undated photo; displaying at the user interface, by the processor, a data structure having a plurality of data nodes, each data node representing one or more data records having a subject associated with one or more dates; identifying at the displayed data structure, by the processor, one or more data nodes that have a relationship to the undated photo based on the estimated image capture date of the undated photo and the dates associated with the subject of the one or more data nodes; displaying, by the processor, a tagging data entry window at the user interface for receiving tagging information from a user viewing the undated photo and the displayed data structure; and receiving, by the processor, tagging information at the tagging data entry window at the user interface concerning the undated photo based on the identified one or more data nodes.