Subtract Two Date Fields to Calculate Duration of Time
{"Image Artist": "Martin", "Image ExifOffset": "2130", "Image XPAuthor": "Martin", "Image Padding": "[]", "EXIF DateTimeOriginal": "2014:09:06 21:57:36", "EXIF DateTimeDigitized": "2014:09:06 21:57:36", "EXIF SubSecTimeOriginal": "22", "EXIF SubSecTimeDigitized": "22", "EXIF Padding": "[]"}