Geotag and image date and time

[jgalea]

What are you using as the date and time of a photo when you compare against the GPS track, it is the actual date and time on the file or the date and time inside an EXIF tag? The reason I ask is when I edit the photo using Paint.net the dates are getting messed up as far as exiftool being able to match against the GPS track, so I am just trying to figure out what I need to fix ... Thanks for your time.

[StarGeek]

See Geotagging with ExifTool, -GeoTime.
    If a value for Geotime is not given, it is taken from unformatted value of DateTimeOriginal for each image (as if "-Geotime<DateTimeOriginal#" had been specified), but the value may be copied from any other date/time tag or set directly from a date/time string.

DateTimeOriginal is normally set to the local time where the image was taken and doesn't normally contain a time zone.  So you will have to adjust that local time to sync up with the GPS time, which is UTC.  Either by use of -GeoSync or by specifically setting Geotime with the time zone added manually e.g. "-Geotime<${DateTimeOriginal}-08:00" or by setting it from a tag that includes the time zone if it exists e.g. "-GeoTime<FileModifyDate"