FAQ: Setting the Time Zone using GOTOES.

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fulmar2
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FAQ: Setting the Time Zone using GOTOES.

Post by fulmar2 »

I get a lot of questions on how to set the time zone using GOTOES GPS Tools... This post attempts to help you solve the issue of incorrect start times on Strava after using the GOTOES tool.

SHORT ANSWER:

There are two things to check:
  • Is your time zone set correctly in your Strava profile?
  • Was this an indoor workout with a map? If so, you need to select "Zwift" (or other indoor trainer as your GPS type) and "Virtual Ride" as your Activity Type when you export from GOTOES.
If you use the Zwift (or Peloton or FulGaz, Rouvy, or Wattbike, etc..) selection... along with "Virtual Ride," this will tell Strava that it was an indoor workout and Strava needs to use the time zone in your profile instead of trying to calculate your time zone from the fake GPS coordinates in your activity.
If you use the Zwift (or Peloton or FulGaz, Rouvy, or Wattbike, etc..) selection... along with "Virtual Ride," this will tell Strava that it was an indoor workout and Strava needs to use the time zone in your profile instead of trying to calculate your time zone from the fake GPS coordinates in your activity.

That should get you fixed... but what follows next is the nitty gritty on how time zones work on Strava.


LONG ANSWER

The issue is: You Can't store the time zone on GPX or TCX files, as these file types simply don't allow for this type of information.. It is only with FIT exports that can you specify the time offset.

Gotoes has a time zone drop down menu, but for GPX and TCX the only purpose of the selection for loaded GPX/TCX files is so that when you get the sorted, graphical display of your loaded files, you can see the time in a familiar time zone.

Your selection of Time Zone controls the time displayed here.  However, when you export as GPX, TCX, or KML, the timestamps are still recorded in UTC (the time zone at the prime meridian).
Your selection of Time Zone controls the time displayed here. However, when you export as GPX, TCX, or KML, the timestamps are still recorded in UTC (the time zone at the prime meridian).

GPS files are always recorded in the UTC time zone. This is the time zone at the prime meridian (the opposite end of the globe from the international date line).

For example, let's say you are in Los Angeles, California USA. During Daylight Savings time, we call the time in Los Angles "UTC -7 hours". During the winter, we call it "UTC -8 hours". If you're in Los Angles in the winter, and you push the start button at 8:00AM, the time in your file will be recorded as 16:00 (This is 8:00AM PLUS 8 hours so it matches up with UTC as mentioned previously: "UTC -8 hours".... which is 4:00PM). If you recorded in Los Angles during Daylight Savings Time, and you pushed the start button at 8:00AM on your device, it would be recorded in the GPS as 15:00 (This is 8:00AM PLUS 7 hours so it matches up with UTC as mentioned previously: "UTC -7 hours".... which is 3:00PM).

So, if the only time information in the file is the start time in some other locale (UTC), how does Strava know what time you really started the activity? The answer is: It's complicated. I can think of 3 different ways Strava determines your actual start time, depending on what you upload:

#1 You upload a GPX or TCX file for an Outdoor Workout

GPX and TCX files do not have anywhere to save time-zone information. So, If you upload a track recorded outdoors with position data (latitude / longitude), Strava looks at the GPS coordinates of your file, and it determines what time zone you are in, and offsets the UTC timestamps in your file by the difference in time between the time at your longitude and the time at the prime meridian. Simple, right?

#2 You upload a GPX or TCX file for an Indoor Workout

As stated above, GPX and TCX files do not have anywhere to save time-zone information. So now what? You can't calculate the time zone as described above because for indoor workout, there is no map (unless you're using Zwift, which can generate a fake map and fool Strava into thinking you were in the South Pacific time zone because of the map)** Strava uses the time zone saved in your profile. If you haven't already done https://support.strava.com/hc/en-us/art ... Start-Time


#3 FIT Files - indoor or outdoor

Fit file export allows GOTOES to insert the "time zone offset" for both indoor and outdoor workouts. The time zone offset will be based on whatever timezone you select (and if you don't select a time zone, the tool will try and "guess" the time zone for you).

Outdoor workouts, FIT Export

These usually present no problem with Strava or Garmin Connect.

Indoor workouts, FIT Export

The issue with indoor workouts is that even though GOTOES embeds the correct time offset, Strava may ignore it! If you do an indoor workout that has a map and do not tell Strava that it was an indoor workout (Virtual Ride), strava will use the timezone for your map instead. Therefore, for indoor workouts, you MUST select "Virtual Ride" and an indoor compatible GPS type as described below:


**When you select the GPS type in GOTOES, you're telling also telling Strava a little about if your recorded activity was real or virtual. This can have an impact on your activity start time:
If you select a regular GPS in GOTOES for an indoor trainer workout recorded with a map (like Zwift), expect to get a weird time zone on Strava! This is because Strava will see the map and think you really were riding on some island in the South Pacific!
If you select a regular GPS in GOTOES for an indoor trainer workout recorded with a map (like Zwift), expect to get a weird time zone on Strava! This is because Strava will see the map and think you really were riding on some island in the South Pacific!
If you use the Zwift (or Peloton or FulGaz, Rouvy, or Wattbike, etc..) selection... along with "Virtual Ride," this will tell Strava that it was an indoor workout and Strava needs to use the time zone in your profile instead of trying to calculate your time zone from the fake GPS coordinates in your activity.
If you use the Zwift (or Peloton or FulGaz, Rouvy, or Wattbike, etc..) selection... along with "Virtual Ride," this will tell Strava that it was an indoor workout and Strava needs to use the time zone in your profile instead of trying to calculate your time zone from the fake GPS coordinates in your activity.
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