How Are Time Periods Supported in Compute and Input Variables?

Forsta Visualizations has support for using floating time periods in expression when computing categorical variables like for example “Last 2 months”. This makes it easier and more efficient to make special comparisons like for example “Latest month” compared to “Same month last year” without having to do any manual updates when new data is loaded in a tracker.

Setup

When computing categorical variable and using Date variables in the expressions the following can now be used in the expressions

• “Last X days”
• “Last X weeks”
• “Last X months”
• “Last X quarters”
• “Last X Years”

X= any whole number

Below you see a couple of example expressions:

• ♮1100000000001-Response Date♮ = "Last 1 week" > will include all respondents with an interview date belonging to the last 1 week
• ♮1100000000001-Response Date♮ = "Last 13 months" > will include all respondents with an interview date belonging to the last 13 months

By for example combining two floating time periods you can now easily compare the last month to the same month last year by computing a variable with 2 answers which both uses a floating time period see example below.

• Answer 1, Last month; (♮1100000000001-Response Date♮ = "Last 1 month")
• Answer 2, Same month last year; (♮1100000000001-Response Date♮ = "Last 13 months") AND NOT (♮1100000000001-Response Date♮ = "Last 12 months")

Note: The “last month”, “last week” etc. is calculated on the most recent response date and not by today’s date, it is the same logic as is used in charts and tables when applying floating time periods.

Example: 

A project has data until the 27th of April 2018,

• Last 1 Day = 27th of April 2018
• Last 1 Week = week 17
• Last 1 Month = April
• Last 1 Quarter = Quarter 2
• Last 1 year = 2018

Note: when using time periods in combination with other expressions, it's important to have the time period selection at the beginning of the expression

So for example:  (∅9000000000036-Alerts=('3 - Closed')∅) AND (♮1100000000001-Response Date♮ = "Last 3 months") should be (♮1100000000001-Response Date♮ = "Last 3 months") AND (∅9000000000036-Alerts=('3 - Closed')∅)