I didn't hear back from Evernote support, so I solved the problem myself. Here is the comment section of the python script I wrote:
# This script helps corrects inconsistent date formats between Evernote 10 and .enex files exported from Evernote Legacy.
# For a given .enex file, the script finds every occurrence of the form:
# "<created>2023-09-15T17:49:22.631Z</created>"
# and replaces it with
# "<created>20230915T174922Z</created>"
# which is the format that Evernote 10's import function assumes.
# Similarly, the script finds every occurence of the form:
# "<updated>2023-09-15T17:49:47.631Z</updated>"
# and replaces it with
# "<updated>20230915T174947Z</updated>"
# On completeion, the script reports how many replacements of each type were made.
# This script defines a function modify_dates_in_file which takes the path to the file as an argument. It uses regular expressions to
# find and replace the patterns for 'created' and 'updated' dates, and then writes the modified content back to the file. Finally, it
# prints the count of replacements made for each type.
# Remember to replace 'your_Legacy_export_file.enex' with the actual path of your file.
If you are an Evernote user, and would like the code, contact me. Please do not redistribute without my permission.
If you are an Evernote developer, and would like the code so you can fix this problem for your users (it will be of use even after Legacy is decommissioned, as long as the .enex files were exported before then), please get in touch and I'm sure we can work something out.
