Follow these steps:

  1. Configure your options:
    • If you keep all the fields empty, ALL your photos will be processed. You can restrict the batch with the dates below.
    • Dates format is: YYYY-MM-DD hh:mm:ss. hh:mm:ss is Optional
    • If you wish to only process photos from a set, enter the set id in the 'Photoset id' field
    • If you wish to only process photos with particular tags, enter comma-separated tags in the 'Tags' field (can be combined with dates)
    • If you wish to process a single photo, enter its Id in the 'Photo id' field
  2. Read the further steps and then click GO, you will be redirected to Flickr for authentication (example page).
  3. Hit Ok, I'll allow it. This will grant this app the rights to write the correct upload date to your photos
  4. Photos are processed by batch of 100 photos so click 'Process the next XXX' until you reach the end
  5. If you like this tool you might consider buying me a beer by way of thanks.