Re: how to find the sum of total in particular date
you want to find the total of items in a particular daterange? Do you have those ranges as fixed intervals?
If so, you could use the IntervalMatch() function to join every single date to a particular interval -> Then you could just count the items across the dimension >intervals<.
You could also do it dynamically on the GUI - that is a bit more resource-intensive, but possible: The user can select a from_date and a to_date and you count and use a set_expression specifying that the [date] be >= the from_date and <= the to_date.