Bug Report: ConversionUploadService returns an invalid date format error despite valid input (v21 API)

[Dmytro Zinovyev]

Subject: Bug Report: ConversionUploadService returns an invalid date format error despite valid input (v21 API)

Body:

Hello Google Ads API Support Team,

We are encountering a persistent issue when uploading offline conversions via the Google Ads API (v21). We have been consistently receiving a conversion_date_time format error, even though we have provided data that conforms to the official documentation and the format specified in the API's own error message.

Problem Description:

We are attempting to upload a single offline conversion using the ConversionUploadService.upload_click_conversions method. The API consistently returns an INVALID_ARGUMENT error with the following message: The string date time's format should be yyyy-mm-dd hh:mm:ss+|-hh:m., at conversions[0].conversion_date_time

Steps to Reproduce (already performed on our end):

To rule out any issues on our side, we have performed the following isolated tests:

1. We sent a test request using a hardcoded timestamp in the official ISO 8601 format (yyyy-MM-dd'T'HH:mm:ss+HH:mm) as per the documentation.

   • Result: The request was rejected with the error message shown above.

2. We modified the timestamp to exactly match the format requested in the API's error message (yyyy-mm-dd hh:mm:ss+|-hh:m.).

   • Result: The request was rejected again with the exact same error.

3. We tried a third common format (yyyy-mm-dd hh:mm:ss+HHMM).

   • Result: This request was also rejected with the same error.

This behavior suggests that the API is not accepting the date format that it is explicitly requesting.

Technical Details for your Investigation:

• Customer ID: (Please insert your Customer ID here)

• API Version: v21

• Test GCLID: Cj0KCQjw5FbHcyARisAHBx2wwiOd3WlMtlp71db_n4dZEpXx1ld_izq7_lybphj-ASLxsWbo2SOCcwaAgZ4EALw_wcB

• Conversion Action ID: 7265775359

• conversion_date_time value we sent: "2025-08-22 06:52:17+0000"

• Request ID: (Please find this value in your full logs and insert it here)

We kindly ask you to investigate this issue and provide us with a solution or a valid workaround, as we are unable to successfully submit conversions at this time.

Thank you for your assistance.