When was that?: Maintaining or changing ‘created’ and ‘last modified’ dates

Sarah has recently been testing scenarios to investigate the question of changes in file ‘date created’ and ‘last modified’ metadata. When building training, it’s always best to test out what your advice before giving it and below is the result of Sarah’s research with helpful screenshots.


Before doing some training that involved teaching better recordkeeping habits to staff, I ran some tests to be sure that I was giving the right advice when it came to created and last modified dates. I am often told by people in the field that these dates are always subject to change—but are they really? I knew I would tell staff to put created dates in file names or in document headers in order to retain that valuable information, but could the file maintain the correct embedded date anyways?  I set out to test a number of scenarios on both my Mac OS X laptop and Windows desktop.

Scenario 1: Downloading from cloud storage (Google Drive)

This was an ALL DATES change for both Mac OS X and Windows.

Scenario 2: Uploading to cloud storage (Google Drive)

Once again this was an ALL DATES change for both systems.

Note: I trialled this a second time with the Google Drive for PC application and in OS X and found that created and last modified dates do not change when the file is uploaded or downloaded the Google Drive folder on the PC. However, when in Google Drive via the website, the created date is different (the date/time of upload), though the ‘file info’ will confirm the date has not changed. Just to complicate things.

Scenario 3: Transfer from a USB

Mac OS X had no change to the dates. Windows showed an altered created date, but maintained the original last modified date.

Scenario 4: Transfer to a USB

Once again there was no change of a dates in the Mac OS X. Windows showed an altered created date, but maintained the original last modified date.

Note: I looked into scenarios 3 and 4 for Windows a bit further and saw that Robocopy is an option as a command prompt that will allow directories to be copied across and maintains those date attributes. I copied a ‘TEST’ folder containing the file from the Windows computer to the USB, and back again. It did what was promised and there were no changes to either dates in the file. It is a bit annoying that an extra step is required (that many people would find technically challenging and therefore avoid).

Scenario 5: Moving between folders

No change across either systems. This was a relief for me considering how often I move files around my directories.

Conclusions

When in doubt (and you should always be in doubt), test the scenario. Even when I tested these scenarios three of four times, it did not always come out with the same result. That alone should make one cautious. I still stick to putting created date in the file name and in the document itself (where possible), but it doesn’t meant I always receive documents that way.

Creating a zip of files/folders before transfer is one method of preserving dates, but I had some weird issues trying to unzip the file in cloud storage that took a few tries before the dates remained preserved. It is also possible to use Quickhash for transferring files unchanged (and it generates a checksum).

I ignored the last accessed date during testing, because it was too easy to accidentally double-click a file and change it (as you can see happened to my Windows 7 test version).

Has anyone tested any other scenarios to assess when file dates are altered? Does anyone have methods for transferring files without causing any change to dates?

Training begins: personal digital archiving

Outreach & Training Fellow, Sarah, has officially begun training and capacity building with session on personal digital archiving at the Bodleian Libraries. Below Sarah shares how the first session went and shares some personal digital archiving tips.


Early Tuesday morning and the Weston Library had just opened to readers. I got to town earlier than usual, stopping to get a Melbourne-style flat white at one of my favourite local cafes – to get in me in the mood for public speaking. By 9am I was in the empty lecture theatre, fussing over cords, adjusting lighting and panicking of the fact I struggled to log in to the laptop.

At 10am, twenty-one interested faces were seated with pens at the ready; there was nothing else to do but take a deep breath and begin.

In the 1.5 hour session, I covered the DPOC project, digital preservation and personal digital archiving. The main section of the training was learning about personal digital archiving, preservation lifecycle and the best practice steps to follow to save your digital stuff!

The steps of the Personal Digital Archiving & Preservation Lifecycle are intended to help with keeping your digital files organised, findable and accessible over time. It’s not prescriptive advice, but it is a good starting point for better habits in your personal and work lives. Below are tips for every stage of the lifecycle that will help build better habits and preserve your valuable digital files.

Keep Track and Manage:

  • Know where your digital files are and what digital files you have: make a list of all of the places you keep your digital files
  • find out what is on your storage media – check the label, read the file and folder names, open the file to see the content
  • Most importantly: delete or dispose of things you no longer need.
    • This includes: things with no value, duplicates, blurry images, previous document versions (if not important) and so on.

Organise:

  • Use best practice for file naming:
    • No spaces, use underscores _ and hyphens – instead
    • Put ‘Created Date’ in the file name using yyyymmdd format
    • Don’t use special characters <>,./:;'”\|[]()!@£$%^&*€#`~
    • Keep the name concise and descriptive
    • Use a version control system for drafts (e.g. yyyymmdd_documentname_v1.txt)
  • Use best practice for folder naming;
    • Concise and descriptive names
    • Use dates where possible (yyyy or yyyymmdd)
    • keep file paths short and avoid a deep hierarchy
    • Choose structures that are logical to you and to others
  • To rename large groups of image files, consider using batch rename software

Describe:

  • Add important metadata directly into the body of a text document
    • creation date & version dates
    • author(s)
    • title
    • access rights & version
    • a description about the purpose or context of the document
  • Create a README.txt file of metadata for document collections
    • Be sure to list the folder names and file names to preserve the link between the metadata and the text file
    • include information about the context of the collection, dates, subjects and relevant information
    • this is a quick method for creating metadata around digital image collections
  • Embed the metadata directly in the file
  • for image and video: be sure to add subjects, location and a description of the trip or event
  • Add tags to documents and images to aid discoverability
  • Consider saving the ‘Creation Date’ in the file name, a free text field in the metadata, in the document header or in a README text file if it is important to you. In some cases transferring the file (copying to new media, uploading to cloud storage) will change the creation date and the original date will be lost. The same goes for saving as a different file type. Always test before transfer or ‘Save As’ actions or record the ‘Creation Date’ elsewhere.

Store:

  • Keep two extra backups in two geographically different locations
  • Diversify your backup storage media to protect against potential hardware faults
  • Try to save files in formats better suited to long-term access (for advice on how to choose file formats, visit Stanford University Libraries)
  • refresh your storage media every three to five years to protect against loss of hardware failure
  • do annual spot checks, including checking all backups. This will help check for any loss, corruption or damaged backups. Also consider checking all of the different file types in your collection, to ensure they are still accessible, especially if not saved in a recommended long-term file format.

Even I can admit I need better personal archiving habits. How many photographs are still on my SD cards, waiting for transfer, selection/deletion and renaming before saving in a few choice safe backup locations? The answer is: too many. 

Perhaps now that my first training session is over, I should start planning my personal side projects. I suspect clearing my backlog of SD cards is one of them.

Useful resources on personal digital archiving:

DPC Technology Watch Report, “Personal digital archiving” by Gabriela Redwine

DPC Case Note, “Personal digital preservation: Photographs and video“, by Richard Wright

Library of Congress “Personal Archiving” website, which includes guidance on preserving specific digital formats, videos and more