39. The computer program product of claim 31 , wherein the merging of the date formats retains components of the date format for the first text string and components of the date format for the second text string that are common to both formats.
31. A computer program product comprising a computer-readable storage medium, for resolving ambiguities in date values associated with an attribute of an entity, the computer-readable storage medium comprising: program code for obtaining a first text string associated with an attribute of an entity, wherein the first text string is extracted from a first web document; program code for determining that the first text string conforms to one or more date formats; program code for assigning a first confidence value for each of the date formats for the first text string based on a first number of unknown variables that remain when interpreting the first text string using each of the date formats; program code for obtaining a second text string associated with the attribute of the entity, wherein the second text string is extracted from a second web document; program code for determining if that the second text string conforms to one or more of the date formats; program code for assigning a second confidence value for each of the date formats for the second text string based on a second number of unknown variables that remain when interpreting the second text string using each of the date formats; program code determining a first date string expressed in a date format with a highest first confidence value for the first text string; program code determining a second date string expressed in a date format with a highest second confidence value for the second text string; and program code for merging a first subset of the first date string and a second subset of the second date string to obtain a date value for the attribute.