Fixing .fit-File: Timestamps are all over the place due to time in the starting pen?

Bugs and Support
1

Hi all,

I have looked through multiple forums, but couldn’t find a problem just like mine.
I did a group RampTest on Zwift the other day (start time: 06:30 pm) and hopped into the meetup about 14min before the start for a warmup. The activity looks perfectly fine on the zwift web app and in the companion app. But when uploaded to Trainingpeaks or Strava I get all sorts of weird stuff.

In Zwift the activity is just under 30min long.
No Problems here.

In Trainingpeaks it is about 44min long.
When analysing, 14m24s with no data got added to the start of the activity (my warmup). Start time is still 06:30pm. The last 14min or so are displayed without any graphs for power, cadence, hr, etc., but when hovering over the empty part of the activity, I still get shown the data??? This data does contribute to new Peaks that I achieved in this activity. The Laps for this activity are timed correctly and start at the very beginning, which means the data for the laps starts 14min late.

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In Strava it is just about 15min long.
Here the Activity starts with the correct data straight away (compared to Trainingpeaks), but the start time is set to 06:44 (might hint at the first empty 14min displayed in Trainingpeaks). The last 14min (which couldn’t be displayed in Trainingpeaks, but still had data in them) are completely cut off in Strava, making the activity just 15min long.

I have tried deleting and reuploading the .fit-file manually.
I have tried to correct the activity with fitfiletools, but both the “time adjuster” and the “corrupt time fixer” don’t fix it. In fact, nothing changes at all when I upload those activities.

I also converted the .fit-file from Zwift to .csv and looked at the raw data, but that just got me more confused. The timestamps of the individual data points start at 10:44:27, which makes zero sense to me.

My only idea is to convert the .fit-file to csv, change the timestamps for every datapoint manually and try to get it back into a .fit-file. But unfortunately, the format of the timestamps is nonstandard, so no bulk reformatting in Excel, which means I would have to correct thousands of timestamps manually.

If there is an easy way to fix this, I’d be glad to learn about it, but otherwise it’s not important enough for me to adjust thousands of datapoints manually…
Thanks in advance everyone! Cheers!

2

Did you find a fix for this?

My partner has a similar issue. The time spent in the pen before a group ride is deducted from the Strava activity length (so the distance and time in Strava don’t tally up with the Zwift activity). Oddly some of the other data matches

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3

This is the case IRL too. Strava doesn’t count time spent stationary and while in the pen, you’re not moving anywhere.

4

Sorry I might not have been very clear. I agree with you that non moving time should not count.

For example, say you join a 45 minute group workout, you enter the pen 5 minutes early. The activity on Zwift is correct, but the ride on Strava will be 40 minutes, it looks to have an issue with incorrect ride ending time within the data transfer so cuts the ride short. And looks to be deducting the time sat in the pen from the actual activity time.

Hence why the distance between the Zwift data and Strava data don’t match (same with the activity time and Strava moving/elapsed time) for the same ride

Oddly this only seems to occur on group workouts, not group rides/races.