Can I calculate how many hours an minutes have gone from an Epoch time and until now in a function node?

General
1

I'm adapting a Norwegian gas prices flow to my use. It had a lot of UI stuff, which I have removed. And I have the function node that goes before the sending over MQTT down to this:

msg.topic = "Bensinstasjoner"
var kjede = msg.payload.brand;
var navn = msg.payload.name;
var tid = new Date(parseInt(msg.payload.prices.B95.lastUpdated)*1000);
msg.payload = kjede+' ' +navn+': '+msg.payload.prices.B95.price +' klokka '+tid;
return msg;

The line with the variable tid (time) gives me in a human readable form the time that the price was updated. But I would like to have an hour and minutes value instead. Can I use the Epoch time that comes in (for instance 1740980811053, which was about two hours and 30 minutes ago at the time of writing) in that function node to get that output, and if I can, how?

2

You can use days.js or moments.js in the function node. There are numerous examples on the forum of how to uses these libraries in a function node, using the setup tab.

Both libraries have similar syntax and have a diff function.

3

Thank you! I will look around, then.

4

Since that is the epoch time in msec then in a function node you can get the current time, convert to msec and subract the two. Something like
const diff = new Date().getTime() - parseInt(msg.payload.prices.B95.lastUpdated)*1000

Then you can easily convert to hours and minutes.
If you need help with that then searching for
How to convert milliseconds to hours and minutes using javascript
will soon provide a solution.

5

Thanks! I had arrived at something very close to that (only with one more line), and I am looking for the conversion now.

6

This works as I wanted it to! :grin: Thanks for the pointers!

msg.topic = "Bensinstasjoner";
var kjede = msg.payload.brand;
var navn = msg.payload.name;
const diff = new Date().getTime() - msg.payload.prices.B95.lastUpdated;
var timer = Math.floor(diff/1000/60/60);
var minutter = Math.floor((diff/1000/60/60 - timer )*60);
msg.payload = kjede+' ' +navn+': '+ msg.payload.prices.B95.price +' for '+ timer +' timer og ' + minutter + ' minutter siden';
return msg;

image
image429Ă—116 4.52 KB

7

it take seconds as input

function runtime_str_sec (sec, format) {
    const t = sec;
    const h = (Math.floor(t / 3600)).toString().padStart(3, '0');
    const m = (Math.floor(t % 3600 / 60)).toString().padStart(2, '0');
    const s = (Math.floor(t % 3600 % 60)).toString().padStart(2, '0');
    switch (format) {
        case "HH:MM:SS":
            return `${h}:${m}:${s}`;
        case "HH:MM":
            return `${h}:${m}`;
        case "HH":
            return `${h}`;
    }
}
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