Bulk update from CSV - Dates importing incorrectly

[Michelle Prosser-Roberts]

Hi community

I imported a number of work items using the Bulk import CSV option.  While the mapping of data looked to be working correctly, when I examined the imported data in Jira, the date fields (Duedate and Custom Field Start date) were imported incorrectly.
I set the date format correctly to match my csv file (dd/mm/yyyy) and double checked the data mapping for each input date.

I thought I must have missed something so I then tried to update the date fields using the External System Import, but experienced the same issue.

As an example, if this was what I was Importing or Updating:

Custom field (Start date): 01/04/2025                      

Due date:  30/06/2025

after import I would see:

Custom field (Start date): 01/01/2025                      

Due date: 30/01/2025

Below is a screen shot of the values that I should have seen uploaded i.e. standard quarter dates that I double checked.

But what I got was Jan dates for all dates. It appears to have ignored the Month part of the date and defaulted to Jan - which appears to be the pattern for Due Date.

Any pointers or suggestions appreciated :)

[Manoj Gangwar]

Hi @Michelle Prosser-Roberts Welcome to the Community!

Could you please check the imported issue history and see if the date was updated after issue creation via automation or workflow post functions?

[Michelle Prosser-Roberts]

Thanks for responding Manoj,

Nothing in the work history that would suggest this. And at this stage, and as it is a new project I haven't created any automations or workflow transitions yet either.

Its perplexing and weird.  Not sure I like weird :)

And when I check the log of the import / update the only reference is:

2025-04-10 07:14:36,257 INFO - 20 issues successfully updated

It doesn't identify the fields updated .

So apart from a pattern that is showing that the month is not translating I have nothing to go on.
Having just written that, it gave me an idea which I will try out and report back.
I will change the format of my dates to dd/MMM/yyyy which is the format that dates are displayed in Jira and see if that "fixes" my problem.  It would still be perplexing but wouldn't be weird :)

[Michelle Prosser-Roberts]

OK - well that fixed it.

So when I imported dates in a format dd/mm/yyyy it lost the month and defaulted everything to January.  As can be seen in the table above in my first post.

When I changed the date format in the CSV and the corresponding import date format to be dd/MMM/yyyy it uploaded successfully.

While I have solved the issue for me, I would still think that this was a bug as it allows you to choose the simple date format of choice.  https://docs.oracle.com/javase/1.5.0/docs/api/java/text/SimpleDateFormat.html