topic Re: AGOL Arcade Question Date Difference in ArcGIS Online Questions

AGOL Arcade Question Date Difference

LukeAllen2 — Fri, 12 Feb 2021 17:24:10 GMT

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."
}

Re: AGOL Arcade Question Date Difference

DavidPike — Fri, 12 Feb 2021 18:27:19 GMT

that's an interesting one. Can you get the number of years difference, say 2.11 then e.g. create a new variable where you add 2 years to survey, then compare DateDiff(,,'days')

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Fri, 12 Feb 2021 20:04:35 GMT

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 && d > 1) {
return "Last Painted: " + Round(d , 0) + " days ago."
} else if (y == 0 && d <= 1) {
return "Last Painted: " + Round(d , 0) + " day ago."
}

Still playing around with it, and getting myself slightly more confused as this point!

When comparing the duration I'm getting from the above code its not quite the same as most online time duration calculators - actually short by 2 days -- is there something obvious that I missing here? (See attachment for context)

Re: AGOL Arcade Question Date Difference

DavidPike — Fri, 12 Feb 2021 20:20:41 GMT

Try changing the inputs about in the arcade playground ArcGIS Arcade | ArcGIS for Developers and see if this suits:

var a = Date('2021-02-12 00:00:01') var b = Date('2020-01-14 00:00:01') var years = Floor(DateDiff(a,b,'years')) var days = DateDiff(a,DateAdd(b, years, 'years'),'days') return "Last Painted: " + years + " years and " + days + " days ago."

Re: AGOL Arcade Question Date Difference

KenBuja — Fri, 12 Feb 2021 20:24:14 GMT

You checked the option "Include end date in calculation", which doesn't not make sense in your case. For example, if you calculate the difference between 1/1/2020 and 1/2/2020 with the option checked, it returns 2 even though it's only one day later.

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Sat, 13 Feb 2021 00:34:15 GMT

Hi David, thank you I think your code is alot more stream lined and I'll use that with a few adjustments to catch those that were painted today, yesterday or within the same year etc.

Many thanks !

Re: AGOL Arcade Question Date Difference

DavidPike — Sat, 13 Feb 2021 01:41:15 GMT

Good stuff, In my head it works conceptually, (let the datetime module do the work - I'm guessing that's what its based on??) A few If Elses for the formatting and should be good. I hope the concept kinda makes sense.

Re: AGOL Arcade Question Date Difference

XanderBakker — Sat, 13 Feb 2021 22:01:44 GMT

Hi @LukeAllen2 ,

I think this thread is related to what you send me by private message. You can use a function that will determine the number of days in a year (taking into account the leap years):

And below the complete expression:

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Mon, 15 Feb 2021 19:48:43 GMT

Hi all, Xanders expression seems to work great in the arcade test area of the expression builder, but when I add it to the popup nothing shows, ive no idea what could be causing that to happen?

Re: AGOL Arcade Question Date Difference

XanderBakker — Mon, 15 Feb 2021 20:03:47 GMT

Hi @LukeAllen2 ,

Can you validate if the feature has a painted date and can you see in the developer options of the browser if there is any error message when you click on the feature?

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Mon, 15 Feb 2021 20:15:43 GMT

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

Re: AGOL Arcade Question Date Difference

XanderBakker — Mon, 15 Feb 2021 21:19:39 GMT

Hi @LukeAllen2 ,

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

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Mon, 15 Feb 2021 21:22:15 GMT

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

Re: AGOL Arcade Question Date Difference

XanderBakker — Mon, 15 Feb 2021 21:29:03 GMT

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...)

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Mon, 15 Feb 2021 21:32:26 GMT

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

Re: AGOL Arcade Question Date Difference

XanderBakker — Tue, 16 Feb 2021 13:37:09 GMT

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:

Re: AGOL Arcade Question Date Difference

DavidPike — Tue, 16 Feb 2021 13:48:22 GMT

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

Re: AGOL Arcade Question Date Difference

XanderBakker — Tue, 16 Feb 2021 14:15:47 GMT

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

Re: AGOL Arcade Question Date Difference

LukeAllen2 — Wed, 17 Feb 2021 12:20:12 GMT

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 🙂

Re: AGOL Arcade Question Date Difference

AbiDhakal — Tue, 23 Apr 2024 21:01:41 GMT

@XanderBakker @LukeAllen2

- I have this expression that calculates years and populates a field called 'Age'. It gets this information to calculate years from a field called EstbYear (as you can see in the expression below) that I populate with the year it was established. However, it puts the years in the 'Age' field only after the layer is checked and unchecked in the web map. With this happening, another field calculation that relies on 'Age' is not getting calculated unless I go back in and put the age manually first, before I put in the other variables for the calculation to happen

This is the calculation I used which is working just fine:

var currentTime = Year(Now());
var survey = $feature["EstbYear"];

// Calculate age in years
var age = 0;
if (!IsEmpty(survey)) {
age = currentTime - survey;
}

return age;

Is there something I am missing. Do I have to tell somewhere that the next calculation needs to double check the 'Age' field so it can calculate the next field. Do I need to put something in the arcade rule in ArcGIS Pro for the calculation to recognize 'Age' field to so it can see the 'Age' field value to do the next calculation?

Thank you for your help,
Abi