Compare Actual Time with Node-Red Time

General
1

Hi all,

is it possible to compare the actual time to a given time and act accordingly ?
The code that I already have looks like this, but I do not how know to get the actual time from node-red and compare it to a planned time:

IF (pump_status == "ZP1"){
    IF (06:00)  set switch_Status = "ON";
    IF (06:02)  set switch_Status = "OFF";
    IF (07:00)  set switch_Status = "ON";
    IF (07:00)  set switch_Status = "OFF";
}

IF(pump_status == "ZP2"){
    IF(09: 00)  set switch_Status = "ON";
    IF(09: 05)  set switch_Status = "OFF";
    IF(11: 15)  set switch_Status = "ON";
    IF(11: 22)  set switch_Status = "OFF";
}

if (switch_status == "ON" && pump_status == "OFF")   return [msg,null];  // Turn On
if (switch_status == "OFF" && pump_status == "ON")   return [null,msg];  // Turn Off
2

You can get the current local time in Node-RED as a string with a function node containing the following:

msg.payload = time();
function time() { return { time: new Date().toLocaleTimeString() } };
return msg;

You can read more about the JavaScript Date object here: Date - JavaScript | MDN

3

Yes, of course.

However, you will find it a LOT easier if you use one of the existing contributed nodes that will do this comparison for you. For example, the CRON+ node lets you set outputs based on time of day as do several other nodes. For example, I often use node-red-contrib-sun-position instead of node-red-contrib-cron-plus. Depends on what you find easiest and most convenient.#

But here is a more complex example from one of my lights - it is using CRON+ directly. But the sun-position nodes are used elsewhere to set wake/sleep and daylight/nighttime flags via MQTT.

image
image690×588 45.9 KB

4

unfortunately this gives a wrong timezone

image

it is 22:52 right now, but the query says it is 20:52

5

It says it is 2052 UTC (that is what the Z means) so I expect that is the right time, just displayed differently. 20:52 UTC is the same time as 22:52 UTC+2. In what format is the time that you want to compare it with? Where is that timestamp coming from?

6

Yes that could be the case.
UTC is 2hrs behind my local time.

I want to compare with local time - right now it would be "23:16"
The timestamp comes from new Date().toLocaleTimeString()
The Value on top is the debugger timestamp

7

In that case use this:

// get a timestamp
const event = new Date();
// convert to local time
msg.payload = event.toLocaleTimeString("en-US", { timeZone: "Europe/Berlin" });
return msg;
8

I meant where is the time that you want to compare with the current time coming from and what format is it in?

9

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