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