Error for bulk updating dates for sub-task

[keerthi_guntupalli]

I am trying to bulkupdate dates against 2 custom fields for exisitng issues, however i am using the same format that i used previously for a different date field.

Error Example : Cannot add value [ Work item ] to CustomField ["07/06/2026"] in Target start with summary 'ISD - I-ERP0600 - Layout ModuleInterface': fields.validation.date.format

[keerthi_guntupalli]

                             I am mapping all required fields for me , and got around 100 warnings for 400 plus rows,

[Gor Greyan]

Hey @keerthi_guntupalli

One thing I would try is removing the double quotes around the date values. Since these are simple date fields, the CSV values should be like:

Start, Finish
07/06/2026,07/09/2026

Also, make sure the Map field value checkbox is not selected for the date fields. For date imports, Jira should take the value directly from the CSV, not try to map it as a predefined value.

[Gor Greyan]

Hi @keerthi_guntupalli

Welcome to the Atlassian Community!

The error message indicates that Jira is rejecting the value because it doesn't match the expected format for that date field.

Could you let us know how you're performing the bulk update (CSV import, Bulk Edit, Automation, REST API) ?

Also, could you confirm whether Target start is a Date Picker or a Date Time Picker field?

If you're importing dates, Jira typically expects them in the format:

2026-07-06 rather than 07/06/2026

[keerthi_guntupalli]

i am using CSV import, it's a date field and expecting the format mm/dd/yyyy, and while importing aswell i am choosing right date format i was using before when creating which is "mm/dd/yyyy" and in my CSV the value will be "07/09/2026" for 09th July.

Fields using for CSV import 

JIRA Key, Date 1, Date 2, Summary.. where summary is empty

[Gor Greyan]

@keerthi_guntupalli

Thanks for the additional information.

Since you're using a Date Picker field and the same mm/dd/yyyy format works for another field during the CSV import, I don't think the date format itself is the issue.

It makes me think whether the Target start field is configured differently from the other date field or whether the CSV is being mapped to a different field than expected.

Just to help narrow it down, are you able to set the Target start field manually to 07/09/2026 on the same issue? If that works, could you also share a screenshot of your CSV mapping during the import? That should help determine whether the issue is related to the field configuration or the import process itself.

[keerthi_guntupalli]

yes i can manually input the date in the mentioned format.

[Gor Greyan]

@keerthi_guntupalli

Thanks for sharing the screenshot.

The mapping looks correct to me, and since you can also update the Target start field manually using the same date format, it doesn't appear to be a date format or field configuration issue.

Could you share a sample row from your CSV (without any sensitive information removed)? I'd like to compare the values being imported with the field mapping to see if there's anything unusual.

And also, is the error occurring for every work item in the import, or only for specific ones? It may help determine whether the issue is related to the data itself or to a particular work item.

[Jeroen Poismans]

@keerthi_guntupalli , @Gor Greyan 

I see something fishy in you import screenshot. You have ticked the "Map field value" column next to Finish, Jira ID and Start.

Have a look at the documentation of the importer:
https://support.atlassian.com/jira-cloud-administration/docs/import-data-from-a-csv-file/

There is a part in there that explains this toggle:

Set up field mappings

1. ...

2. ...

3. To modify the values of any field in the CSV file before importing into Jira, select the Map field value checkboxes next to the appropriate fields. 

So, what this means is that for every different value of the field you will have t do a manual mapping to another value. Typically used for fields like select fields, status ... etc ..

So for those fields I don't think this checkbox should be ticked.

You want the importer to take the values as is in the import file without manual mapping.

Try that.