Shift an activity's timestamps

A GPS device that didn't update its clock after you flew somewhere new will happily keep recording in the old timezone, so your 7am run shows up logged at 2pm, or worse, on the wrong day entirely. It's a common enough travel problem, and it's also not the only cause — some devices take a few minutes to grab a satellite fix and start the clock, and if you started riding before it locked on, the whole recording can be offset from when you actually started. The fix is straightforward in principle but easy to get subtly wrong by hand: every timestamp in the file needs to move by the same fixed amount, without touching anything else about the recording. The spacing between consecutive points, the total duration, the GPS positions, heart rate, cadence — none of that should change, only the wall-clock time each point is stamped with. Get this wrong and you can end up with a file that has the right start time but compressed or stretched pacing, which is arguably worse than the original problem. FitFileHub's time-shift tool does exactly this one operation: you set the offset — however many hours (and minutes, if needed) the file is off by — and it applies that shift uniformly across every point, preserving the exact interval between them. Before you download anything, it shows you the new calculated start time so you can confirm it now matches when you actually went out, rather than finding out after re-uploading somewhere. This is useful ahead of importing into Garmin Connect, Strava, or TrainingPeaks, all of which will otherwise happily file your activity under the wrong date and time. As with every FitFileHub tool, the shift happens entirely in your browser — the file with your route and timing data is never sent anywhere. Free for files up to 25 MB, three at a time.