SimpleTypes support a mechanism for arranging
 values into groups. 
 These Grouping modes can be applied to any SimpleType, but  some types already support a set of
 builtin modes, as follows: 
 Date Grouping modes 
 -  day/dayOfWeek: Group by
 week-day, all weeks 
-  dayOfMonth: Group by month-day, all months 
-  week:
 Group by Week number, all years 
-  month: Group by Month number, all years 
- 
 quarter: Group by Quarter, all years 
-  year: Group by Year 
-  upcoming:
 Various specific date groups: Today, Yesterday, Last Week, Last Month, etc 
-  date:
 Group by specific Date 
-  dayOfWeekAndYear: Group by week-day, week and year 
- 
 dayOfMonthAndYear: Group by month-day, month and year 
-  weekAndYear: Group by
 week-number and year 
-  monthAndYear: Group by month and year 
- 
 quarterAndYear: Group by quarter and year 
 Time Grouping modes 
 - 
 hours: Group by hours value 
-  minutes: Group by minutes value 
-  seconds:
 Group by seconds value 
-  milliseconds: Group by milliseconds value