# Syncing Time with Cesium and External Application

**URL:** <https://community.cesium.com/t/syncing-time-with-cesium-and-external-application/7899>\
**Category:** CesiumJS\
**Created:** [January 16, 2019, 2:56am UTC](https://community.cesium.com/t/syncing-time-with-cesium-and-external-application/7899 "2019-01-16T02:56:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![RG1](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/rg1/32/2103_2.png) [@RG1](https://community.cesium.com/u/RG1)\
**Post date:** [January 16, 2019, 2:56am UTC](https://community.cesium.com/t/syncing-time-with-cesium-and-external-application/7899/1 "2019-01-16T02:56:06Z")

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**All,**

**How would you go about syncing time/clock up with Cesium and an external application, for example, real-time flight data with time updates every 1-5 seconds or even STK.**

**What would the CZML parameter sets look like and or JS code that would be important in this sort of application.**

**For example:**

**Would you continuously ingest the updated time in the currentTime property in the first CZML packet?**

**Would you continuously ingest the updated time when setting position and quaternion data in the second CZML packet?**

\*\*Would you \*\ ***continuously ingest the updated time when setting epoch position and quaternion in the second CZML packet?**

**Do you need to worry about forwardExtrapolation?**

**Do I need some sort of callback function in the JS code to have a smooth animation?**

**Can someone please point me in the right direction? I’ve scoured the Cesium forum posts for days now and I can’t seem to get anywhere.**

**Please let me know and thank you for looking.**

**1. A concise explanation of the problem you’re experiencing.**

**2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.**

**3. Context. Why do you need to do this? We might know a better way to accomplish your goal.**

**4. The Cesium version you’re using, your operating system and browser.**

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**Author:** ![omar](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/omar/32/1999_2.png) [@omar](https://community.cesium.com/u/omar)\
**Post date:** [January 16, 2019, 5:14pm UTC](https://community.cesium.com/t/syncing-time-with-cesium-and-external-application/7899/2 "2019-01-16T17:14:00Z")

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Looks like the common practice is to run Cesium with a slight time delay if the data is obtained in real time and not simulated, see Scott’s answer here:

[https://groups.google.com/d/msg/cesium-dev/oGN3aW7aPJs/-hfylDxAAgAJ](https://groups.google.com/d/msg/cesium-dev/oGN3aW7aPJs/-hfylDxAAgAJ)

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**Author:** ![RG1](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/rg1/32/2103_2.png) [@RG1](https://community.cesium.com/u/RG1)\
**Post date:** [January 16, 2019, 8:24pm UTC](https://community.cesium.com/t/syncing-time-with-cesium-and-external-application/7899/3 "2019-01-16T20:24:37Z")

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Thank you Omar, I had a few followup questions regarding Scott’s response.

Thanks