add 15 days to date variable

Question

I have the following line of code that pulls a list field date and stores it in a variable called dueDate:

var dueDate = new Date(ctx.CurrentItem.ReminderDate);

How do I create another variable or set the existing one plus 15 days?

Answer 1

Dates are calculated in milliseconds (since 1/1/1970)

with

• 1000 milliseconds in a second
• 60 seconds in a minute
• 60 minutes in an hour
• 24 hours in a day

Each day is 1000*60*60*24 = 86400000 milliseconds

to prevent typos and type less characters you can use the scientific notation: 864e5

So to add 15 days, the JavaScript code is:

var dueDate = new Date(ctx.CurrentItem.ReminderDate);
var anotherDate = new Date( dueDate/1 + 864e5*15 );

The important part is dueDate/1 , where a Date value is converted to milliseconds.

Note that this includes the time part of the date notation, 15*24 hours are added.

If you are developing conditional color formatting with CSR,
see: Conditional Formatting Based on Number Range

CSR note: the this scope in a CSR called function references ctx.CurrentItem

so

var dueDate = new Date(ctx.CurrentItem.ReminderDate);

can be written as:

var dueDate = new Date(this.ReminderDate);