Dynamically swap between Default Calendars on selecting new Tab

[#1]

I am relatively new to QlikView and would like to swap between Default Calendars dynamically when I select a new Tab without having to use Field Event Triggers.  If I could use Variable Event Triggers, I would not have to define separate Field Event triggers for each different Calendar.  I am afraid there is quite a lot to read here before I get to the problem.  Either I have over-complicated things and someone will say "just press the Magic Calendar Button" (perhaps something perhaps not quite that simple) or that there is a simpler way than my approach.  Any help would be much appreciated.

So far I have successfully:

1. Load Script
   • SET Date and Time formats
   • Created the Month and Day names
   • Created a Month Sort order based upon our Financial Year
   • Created the Master Calendars
2. Application
   • Created “”From” and “To” Calendar Objects using variables:
     • vStartDateRange
       • =Min({1} $(eStartDate))
       • =Max({1} $(eStartDate))
     • vEndDateRange
       • =vStartDateRange
       • =Max({1} $(eStartDate))
   • Created "OnActivate Sheet" Triggers
     • Date Name Label Prefix = lDatePrefix (e.g. "Gate ")
     • Date Name Expression Prefix = eDatePrefix (e.g. "Gate")
     • Date Name Abbreviation = DateAbbreviation  (e.g. " Gt ")
     • Date Name Financial Year = eDateFY (e.g. ==eDatePrefix & ' FY')
     • Date Name Quarter = eDateQuarter (e.g. ==eDatePrefix & ' Quarter')
     • Date Name Month= eDateMonth(e.g. ==eDatePrefix & ' Month')
     • Date Name Start = eStartDate (e.g. "GateStartDate").  This is the date field I will filter on for this particular Tab.
   • Created List Boxes for Financial Year, Quarter and Month Using Expressions to identify the Fields

     • [$(eDateFY)] to identify the Field as [Gate FY]

     • [$(eDateQuarter)] to identify the Field as [Gate Quarter]
     • [$(eDateMonth)] to identify the Field as [Gate Month]
   • Created "OnChange" Variable Event Triggers:
     • vStartDateRange
       • Field: =eStartDate
       • Search String: ='>='&vStartDateRange & '<='&vEndDateRange
       • Others that just clear eDateFY, eDateQuarter and eDateMonth fileds (e.g. Field: =eDateFY )
     • vEndDateRange (as above for the Start Date)

Here is the problem:

I have created Field Event Triggers for each of the Date Fields ([Gate FY], [Gate Quarter] and [Gate Month]).  Is there a way that I could use Variable Event Triggers to replicate the actions of the Field Event Triggers shown below?

If these could be Variable Event Triggers, I wouldn't have to repeat the work every time I add a new Calendar.  So, for example (I have done the same for FY, Quarter and Month):

1. For the Field [Gate FY] I have created:
   • OnSelect Field Event Triggers
     • Set Variable
       • Variable: vStartDateRange
       • Value: =minstring($(eStartDate))
     • Set Variable
       • Variable: vEndDateRange
       • Value: =maxstring($(eStartDate))
     • Clear Field
       • Field: ==eDateQuarter
   • OnChange Field Event Triggers (these are convoluted statements to reset the vStartDateRange and vEndDateRange Date Variables.
     • For example
       • =if((GetSelectedCount([$(eDateFY)])=0 and GetSelectedCount([$(eDateQuarter)])=0 and GetSelectedCount([$(eDateMonth)])=0), Minstring($(eStartDate)),  if((GetS..............., nul()))))