AGOL Arcade Question Date Difference

[LukeAllen2]

Hi all,

I'm sort of new to coding in general, but I have started trying to use some arcade expressions in my web maps, currently I have a web map which has a date painted field for hydrants and with the arcade expression below I am using the current date and this field to provide a count of the years and days since a hydrant was last painted.

However, I was QC'ing the data and noticed that for hydrants painted after 2020, it is going to be a day short as 2020 was a leap year - if the web map persists beyond 2024, it will then start being 2 days short.

With my limited knowledge I believe that I need to use some type of when or if statement to be able to use 366 rather than 365 (in var d calculation) i'm just now sure how I would go about doing it - would anybody be able to provide some pointers? 

Many thanks!

var timeNow = Now();
var survey = $feature["DATE_PAINTED"];

var years = DateDiff(timeNow, survey, 'Years');
// 2.1116274159012844

var y = Floor(years, 0);
var d = (years - y) * 365;

if (IsEmpty($feature.DATE_PAINTED)){
return "-"
} else if (y >= 2) {
return "Last Painted: " + Round(y, 0) + " years and " + round(d , 0) + " days ago."
} else if (y == 1) {
return "Last Painted: " + Round(y, 0) + " year and " + round(d , 0) + " days ago."
} else if (y == 0) {
return "Last Painted: " + round(d , 0) + " days ago."
}

[LukeAllen2]

Hi Xander, if you check your PM i sent you a public web map with a snippet of the data im using that replicates the issue

[XanderBakker · Accepted solution]

Hi @LukeAllen2 ,

My bad. Apparently, there is a line missing in the function. Can you try this?

function daysThisYear() {
    // https://stackoverflow.com/questions/16353211/check-if-year-is-leap-year-in-javascript
    var y = Year(Now());
    
    // check leap year
    if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)) {
        return 366;
    } else {
        return 365;
    }
}

var timeNow = Now();
var survey =  $feature["DATE_PAINT"];
// var survey = Date(2015, 1, 1);
var years = DateDiff(timeNow, survey, 'Years');
var y = Floor(years, 0);
var d = Round((years - y) * daysThisYear(), 0);

if (IsEmpty($feature["DATE_PAINT"])){
    return "-";
} else if (y >= 2) {
    return "Last Painted: " + y + " years and " + Floor(d , 0) + " days ago.";
} else if (y == 1) {
    return "Last Painted: 1 year and " + Floor(d , 0) + " days ago.";
} else if (y == 0 && d >= 2) {
    return "Last Painted: " + Floor(d , 0) + " days ago.";
} else if (y == 0 && d >= 1) {
    return "Last Painted: " + Floor(d , 0) + " day ago.";
} else if (y == 0 && d < 1) {
    return "Last Painted: today.";
}

[LukeAllen2]

Xander, that worked!  Thanks again your patience and help!

[XanderBakker]

You're welcome @LukeAllen2 . Sorry for the error in the function. It is a bit weird that it was a valid expression in the expression builder. (I also worked with the error in Pro, when it shouldn't have worked...)

[LukeAllen2]

Xander, no apology necessary - thank you for your time and help -- yeah that was what threw me for a loop too

[XanderBakker]

Hi @LukeAllen2 ,

To reply to the private message you send, have a look at the code snippet below that will take into account the leap year in a more logical way.

// multiple years and days when there is a leapyear
var date1 = Date(2016, 1, 1); // February 1st 2016
var date2 = Date(2020, 2, 1); // March, 1st 2020

// calculate the years as usual
var years = Floor(DateDiff(date2, date1, 'years'));

// create a new date by adding the years to the start date
var date1a = DateAdd(date1, years, 'years');

// calculate the number of days between those date (will account for leap years)
var days = DateDiff(date2, date1a, 'days');

return years + " years and " + days + " days";

And to put this logic in your example, it will look like this:

var timeNow = Now();
var survey =  $feature["DATE_PAINT"];
var y = Floor(DateDiff(timeNow, survey, 'Years'));
var date1a = DateAdd(survey, y, 'years');
var d = DateDiff(timeNow, date1a, 'days');

if (IsEmpty($feature["DATE_PAINT"])){
    return "-";
} else if (y >= 2) {
    return "Last Painted: " + y + " years and " + Floor(d , 0) + " days ago.";
} else if (y == 1) {
    return "Last Painted: 1 year and " + Floor(d , 0) + " days ago.";
} else if (y == 0 && d >= 2) {
    return "Last Painted: " + Floor(d , 0) + " days ago.";
} else if (y == 0 && d >= 1) {
    return "Last Painted: " + Floor(d , 0) + " day ago.";
} else if (y == 0 && d < 1) {
    return "Last Painted: today.";
}

[DavidPike · Accepted solution]

This is the concept I initially posted, @LukeAllen2  did it not work out?

[XanderBakker]

Hi @DavidPike , sorry about that, you are absolutely right. I will mark it as a solution since it is the way to go.

[LukeAllen2]

Hi David, yes this worked, sorry i went down a wormhole with some other issue that Xander was helping me work through and forgot to give credits - thank you 🙂