Temporal tagging (or detection) is the task of finding phrases with temporal meaning within the context of a larger document. For example, detecting "the next 2 weeks" in the sentence "I may go to the store in the next two weeks." This can, in itself, be viewed as a special case of Named Entity Resolution, but drawing much more strongly from contextual cues. To illustrate, "may" or "the 13th" are clearly temporal expressions, but "this may be a temporal expression" and "the 13th floor" are not.
Temporal normalization (or resolution, grounding) is the task of mapping from a textual phrase describing a potentially complex time, date, or duration to a context-independent, easy-to-use temporal representation. For example, possibly complex phrases such as "the week before last" are often more useful in their normalized form – e.g., January 1 - January 7. This is in its own right a difficult problem. To illustrate, "the past" and "3 months" each have independent and very different interpretations, yet "the past 3 months" is completely different from either. In addition, temporal expressions are often ambiguous, either in the syntactic structure (e.g. "[last Friday] the 13th" vs. "last [Friday the 13th]") or its pragmatic content (e.g., "Friday" could be either the previous or next Friday).
Please feel free to e-mail angeli -at- <university> -dot- edu or angelx -at- <university> -dot- edu with any comments or questions.