sym_diff_month: get symmetric difference of months from two vector of R-format dates
Description
sym_diff_month evaluates the symmetric difference between two sets
of R-formatted date
Usage
sym_diff_month(Rdate1, Rdate2)
Value
NULL if no difference; the set of different months otherwise.
Arguments
- Rdate1, Rdate2
R-formatted R dates. See as.Date()