# Skydel Simulation and Receiver time difference

**URL:** <https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327>\
**Category:** Skydel Discussion\
**Created:** [August 22, 2025, 6:01pm UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327 "2025-08-22T18:01:35Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![JasonG\_SFS](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@JasonG\_SFS](https://learn.safran-navigation-timing.com/u/JasonG_SFS)\
**Post date:** [August 22, 2025, 6:01pm UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327/1 "2025-08-22T18:01:36Z")

</div>

Hi!

Would you please help us understand why there is a 10-20 second delay in GPS time between Simulation and Receiver? This occurs when Start time is set to Current Computer Time. Screenshot below from testing.

 ![Time-diff-Sim-vs-Receiver-08-22-25](https://canada1.discourse-cdn.com/flex030/uploads/orolia/original/1X/c717929b9a44cff9d3d0773cfa6764aeb7be933b.png)

---

<div class="post-metadata">

**Author:** ![R-JD](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@R-JD](https://learn.safran-navigation-timing.com/u/R-JD)\
**Post date:** [August 25, 2025, 2:14pm UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327/2 "2025-08-25T14:14:59Z")

</div>

Hello @JasonG_SFS ,

I believe the 18-second delay you’re observing on the Receiver page might be due to the leap second offset between the UTC and GPS time.

Is the time offset constant from one simulation to another? Also, if you set the Leap Seconds parameter to zero on the Settings \> Start Time page, is the time offset still present?

---

<div class="post-metadata">

**Author:** ![JasonG\_SFS](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@JasonG\_SFS](https://learn.safran-navigation-timing.com/u/JasonG_SFS)\
**Post date:** [August 25, 2025, 5:20pm UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327/3 "2025-08-25T17:20:26Z")

</div>

Hi @R-JD

Yes, we had 18s set for the Leap Seconds parameter. I’ve changed that to zero as recommended and no longer see a difference in time between the Receiver and Simulation. Screenshot below from testing.

 ![CurrentComputerTime_0_LeapOffset](https://canada1.discourse-cdn.com/flex030/uploads/orolia/original/1X/d1d6b4e24daf801e0618a25bfae4fcd216ba43f2.png)

Thank you for the quick response!

Much appreciated,

Regards,

Jason G

---

<div class="post-metadata">

**Author:** ![JasonG\_SFS](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@JasonG\_SFS](https://learn.safran-navigation-timing.com/u/JasonG_SFS)\
**Post date:** [August 26, 2025, 8:08pm UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327/4 "2025-08-26T20:08:35Z")

</div>

Hi @R-JD

We have another unit that is showing a 3 second delay between Receiver and Simulation but Leap Sec is set to zero. Are there additional parameters that would cause this? How would we troubleshoot further?

Thanks,

Jason G

---

<div class="post-metadata">

**Author:** ![R-JD](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@R-JD](https://learn.safran-navigation-timing.com/u/R-JD)\
**Post date:** [August 27, 2025, 10:15am UTC](https://learn.safran-navigation-timing.com/t/skydel-simulation-and-receiver-time-difference/1327/5 "2025-08-27T10:15:32Z")

</div>

Hi @JasonG_SFS ,

The delay may be due to the radio initialization time. If that’s the case, arming the simulator before starting the simulation should fix the issue.

Regards,

R-JD