I have captured photos with gopro as usual.
When I match photos with GPX track in JOSM (with auto-guess) and compare if position is OK (ortophoto, cadastre). If not, I try manual adjust +-1-2 second.
Position of sequence was OK, so I just write coordinates and didn't look to time shift closely.
Now date for sequence is jan 2, 2013 but in reality it is may 6, 2017.
It is possible somehow offset time? Or better delete bad sequences and upload with corrected time?