[enriquepablo]

I would say that you are mixing up "parsing" and "calendaring (or something of the sort)". As far as I understand parsing is syntactic analysis, i.e. going from a linear structure to a more complex structure (usually a tree); it should not add to the tree anything that was not in the linear structure. It shouldn't consider a semantic context (such as the current date) to produce an ast.

[mehrdadn]

By parsing I mean it in the usual sense for a date... strptime, Date.Parse, etc... i.e. turning a string to a date (or multiple dates). You can call it something else if you'd like.