void = Reset_FindNextHolidayOnDate()
As with other void functions you do not need to assign the result of this function to any variable :
// look for all holidays on same date
// do something
nDate = nDate + 1 // move on to next date
This macro function is used in conjunction with the function FindNextHolidayOnDate (see the help on that function for a detailed example of how these 2 functions work together). A call to Reset_FindNextHolidayOnDate ensures that your position in the holidays data table goes back to the first entry, so that you do not miss any holiday.