Date Calculations
For ease of use, Knackly evaluates dates with the following functions and determines the outcome.
| Helper Methods | Result Type | Parameters | ||
|---|---|---|---|---|
| parse | date | text or number | ||
| today | date | |||
| addDays | date | base date | number of days to add | |
| addWeeks | date | base date | number of weeks to add | |
| addMonths | date | base date | number of months to add | |
| addYears | date | base date | number of years to add | |
| subDays | date | base date | number of days to subtract | |
| subWeeks | date | base date | number of weeks to subtract | |
| subMonths | date | base date | number of months to subtract | |
| subYears | date | base date | number of years to subtract | |
| age | number | birth date | ||
| new | date | year, month, day | ||
| dayOf | number | |||
| dayOfWeek | number | |||
| daysBetween | number | |||
| monthOf | number | |||
| monthsBetween | number | |||
| yearOf | number | |||
| yearsBetween | number | |||
To help understand the date calculations, we will walk through an example. In many cases, you would want to list children, especially if they are minors. To use a formula to determine if a child is a minor, follow the steps below. You can also watch the accompanying video here:
[embed video]
Open the online workspace and navigate to the BirthDate variable. In most cases, it will be part of the party model. Verify that the BirthDate variable is a date variable.
Select the Formulas tab and Add a new formula. Name it Age and verify that the type is a single number formula.
In the Expression section, enter the formula. In this case, it is date.age(BirthDate). Select Save.
Open the template you are working on. To set up the condition to show a child if they are a minor, we will use an if statement. If you need more details about how to use if statements, review this guide.
We will need an expression that says if a child is younger than 18, then list any details about them here. If they are older than 18, leave this section blank:
{[if Children|any: Age < 18]}
Details
{[endif]}
Note that details is the location to enter in the information that may appear if a child is younger than 18.
Please let us know if you have any comments or suggestions on how to improve this guide.