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spoletto/gist:9383098

Created March 6, 2014 05:23
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The undocumented behavior of ALAssetPropertyDate
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gistfile1.m
/*
* In practice, what I've found is that ALAssetPropertyDate, which is documented as the "asset creation time"
* will return (always in UTC):
*
* (1) If taken from the native camera, a ms-precision time of when the photo was taken.
* (2) If EXIF exists, EXIF time converted to UTC based on the timezone the device was in when
* the photo was saved to the camera roll. This is sec-precision.
* (3) If EXIF does not exist, the time the photo was written into the camera roll. This is sec-precision.
*/
NSDate *timeTaken = [asset valueForProperty:ALAssetPropertyDate];
@igiu1988
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From this article, I found three types of date time in EXIF, so I am wondering which exif time convert to ALAssetPropertyDate? I can't make it out because I don't have a photo that has three different date time.

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