# Calculate the seconds between two timestamps

**URL:** <https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677>\
**Category:** General\
**Tags:** function-node\
**Created:** [23 April 2022 09:42 UTC](https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677 "2022-04-23T09:42:04Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![node2](https://avatars.discourse-cdn.com/v4/letter/n/ea666f/32.png) [@node2](https://discourse.nodered.org/u/node2)\
**Post date:** [23 April 2022 09:42 UTC](https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677/1 "2022-04-23T09:42:04Z")

</div>

i need a function to calculate the difference time in seconds between two clicks, On click and Off click 🙂

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<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [23 April 2022 09:42 UTC](https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677/2 "2022-04-23T09:42:46Z")

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You aren't going to believe this.

I just wrote one.

```auto
[{"id":"93846123e59e8ce9","type":"function","z":"7e987ddf260bdf0d","name":"Time between message arrival","func":"////////////////////////////////////////////////////////////////////////////////\n//\n// How to use\n//\n// `msg.payload` **MUST** be timestanps. So at worst, add a `change` node\n// to set the message as `timestamp`\n//\n////////////////////////////////////////////////////////////////////////////////\n\nvar a = context.get(\"A\") || 0;\n//var b = context.get(\"B\") || 0;\nvar c;\n\nif (a == 0)\n{\n // A\n a = msg.payload;\n// node.warn(\"A = \" + a);\n context.set(\"A\",a);\n return;\n} else\nif (msg.topic == \"B\")\n{\n // B\n b = msg.payload;\n// node.warn(\"B = \" + b);\n}\n\na = context.get(\"A\");\nc = b - a;\n\ncontext.set(\"A\",0);\n\nmsg.payload = c;\n\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":1140,"y":490,"wires":[[]]}]

```

But it will give you the number of MILLISECONDS... So just `/1000` for seconds.

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<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [23 April 2022 09:46 UTC](https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677/3 "2022-04-23T09:46:05Z")

</div>

There is a nice re-usable subflow: [flow-timer. A simple subflow to measure time taken in parts of your flows. (flow) - Node-RED](https://flows.nodered.org/flow/63f29373e826a9fd4943d679d43e725f)

Example...

![chrome_386QBaZIzO](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/0/b/0b2585142f8c12ebba4fa645860a8bb596fa8c28.gif)

Demo flow (use CTRL+I to import)

```auto
[{"id":"9a693308.7ebaf","type":"subflow","name":"flow-timer","info":"","category":"","in":[{"x":80,"y":100,"wires":[{"id":"7fc82258.93e36c"}]}],"out":[{"x":440,"y":100,"wires":[{"id":"7fc82258.93e36c","port":0}]}],"env":[{"name":"name","type":"str","value":"measure","ui":{"icon":"font-awesome/fa-tag","label":{"en-US":"Timer Name"},"type":"input","opts":{"types":["str","env"]}}},{"name":"operation","type":"str","value":"start","ui":{"icon":"font-awesome/fa-cog","label":{"en-US":"Operation"},"type":"select","opts":{"opts":[{"l":{"en-US":"start"},"v":"start"},{"l":{"en-US":"stop"},"v":"stop"},{"l":{"en-US":"msg.topic"},"v":"msg.topic"},{"l":{"en-US":"msg.operation"},"v":"msg.operation"},{"l":{"en-US":"msg.payload"},"v":"msg.payload"}]}}}],"meta":{"module":"node-red-contrib-flow-performance","type":"flow-performance","version":"1.0.1","author":"Steve-Mcl","desc":"Inline flow performance measure node","keywords":"node-red performance","license":"MIT"},"color":"#DAEAAA","icon":"node-red/timer.svg","status":{"x":280,"y":160,"wires":[{"id":"7fc82258.93e36c","port":1}]}},{"id":"7fc82258.93e36c","type":"function","z":"9a693308.7ebaf","name":"do operation","func":"// @ts-ignore\nvar name = msg.perfName || env.get(\"name\");\n// @ts-ignore\nvar operation = msg.perfOperation || env.get(\"operation\");\nvar measures = global.get(\"flow_timers\") || {};\nvar measure = measures[name] || {};\n\nfunction doOp(measure, op){\n if(operation === \"start\"){\n measure.start = Date.now();//change to process.hrtime\n measure.stop = null;\n measure.durationMs = null;\n } else if(operation === \"stop\") {\n measure.stop = Date.now();//change to process.hrtime\n measure.durationMs = measure.start ? measure.stop - measure.start : null;\n msg._performance = measure;\n }\n}\n\n\nif(operation === \"start\"){\n doOp(measure, operation);\n} else if(operation === \"stop\") {\n doOp(measure, operation);\n node.send([null, { payload: { text: name + \": \" + measure.durationMs + \"ms\" }}]);\n} else if(operation === \"msg.topic\") {\n operation = msg.topic;\n doOp(measure, operation);\n} else if(operation === \"msg.operation\") {\n operation = msg.operation;\n doOp(measure, operation);\n} else if(operation === \"msg.payload\") {\n operation = msg.payload;\n doOp(measure, operation);\n} else {\n return [msg, null];\n}\nmeasures[name] = measure;\nglobal.set(\"flow_timers\", measures);\n\nreturn [msg, null];","outputs":2,"noerr":0,"initialize":"","finalize":"","libs":[],"x":250,"y":100,"wires":[[],[]]},{"id":"3863b16330f8d504","type":"inject","z":"79d198b88749c016","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"ON","payloadType":"str","x":610,"y":864,"wires":[["6f1a2bc49f1ca8ee"]]},{"id":"7548488f56eb733b","type":"inject","z":"79d198b88749c016","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"OFF","payloadType":"str","x":610,"y":912,"wires":[["364744c8a7cc9c30"]]},{"id":"6f1a2bc49f1ca8ee","type":"subflow:9a693308.7ebaf","z":"79d198b88749c016","name":"on_off_time start","env":[{"name":"name","value":"on_off_time","type":"str"}],"x":786,"y":864,"wires":[[]]},{"id":"364744c8a7cc9c30","type":"subflow:9a693308.7ebaf","z":"79d198b88749c016","name":"on_off_time stop","env":[{"name":"name","value":"on_off_time","type":"str"},{"name":"operation","value":"stop","type":"str"}],"x":790,"y":912,"wires":[["1bef0bef8f6a22af"]]},{"id":"1bef0bef8f6a22af","type":"debug","z":"79d198b88749c016","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":960,"y":912,"wires":[]}]

```

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [22 June 2022 21:10 UTC](https://discourse.nodered.org/t/calculate-the-seconds-between-two-timestamps/61677/5 "2022-06-22T21:10:03Z")

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