More than once I’ve found myself in a situation where I had happily taken pictures with my digital camera only to discover afterwards that the camera-internal clock was running fast or slow. Whether it’s seconds to a few minutes or whole hour increments due to a forgotten daylight savings time adjustment or travel beyond one timezone – there are situations when you want that time stored in the picture’s meta data to be precise. Thankfully known offsets can be corrected with the help of Phil Harvey’s great piece of software ExifTool, however there are a few tricky details.