dateDiffInYears( )
Calculate the difference between two dates in years. For instance, when you have two questions of type Date in a form.
The dateDiffInYears( ) helper function is invoked with toDate and fromDate passed in as parameters. The function returns a negative or positive number value indicating the difference between the two dates in years. If the number value returned is a negative or zero value, toDate is before or the same as fromDate. If the function returns a positive value, toDate is after fromDate.
Note:
This function is only used to compare variables of type date that do not contain time elements. When using a date/time type parameter, function considers only date part and ignores time elements.
You can use the timeDiffInMinutes( ) helper function to compare two date and time items.
Syntax
dateDiffInYears(toDate, fromDate)
Note:
You must compare dates that have the same format.Return value
Difference between the dates in years (number). This number can be positive or negative.
Note:
The order in which parameters are supplied for date helper functions is important; the resulting return value depends on which date you pass in as the first or second parameter.
Example 3-4 Difference between two Date items
// Given 2 form questions of type Date (with no time elements) are defined in the rule as variables:
return dateDiffInYears(dateItem1, dateItem2);
Example 3-5 Difference between two hard-coded dates
var toDate = new Date("March 1, 2020");
var fromDate = new Date("March 1, 2000");
return dateDiffInYears(toDate, fromDate);
// Returns value: 20
Parent topic: Date and time functions