Difference  Function SummarySummary:Return the difference of two data sets. Usage:difference set1 set2 Arguments:set1  First data set (must be: series bitset date) set2  Second data set (must be: series bitset date) Refinements:/case  Uses casesensitive comparison. /skip  Treat the series as records of fixed size size  The size argument. (must be: integer) Description:Returns the elements of two series that are not present in both. Newer versions of REBOL also let you use DIFFERENCE to compute the difference between date/times.
Date differences produce a time in hours:
There is a limit to the time period that can be differenced between dates (determined by the internal size of the TIME datatype). Note that performing this function over very large data sets can be CPU intensive. Related:intersect  Create a new value that is the intersection of the two arguments.
 
