Issue Summary

This is reproducible on the Data Center: Yes

Steps to Reproduce

• Install Jira (9.12.10)and Confluence (8.5.12)
• In Confluence Navigate to the user profile in Confluence and set the Time zone(GMT+0400) Abu Dhabi, Muscat
• In Jira  Navigate to the user profile in Jira preferences and set the Time zone(GMT+0400) Abu Dhabi, Muscat
• Create an application link between Jira and Confluence.
• Create a release in Jira and set a release date

• In Jira Add a version with a release date to a project as above 
• Now In Confluence add this release date in the team calendar event.

Expected Results

Release dates  should be same in Jira and Confluence Team calendar 

Actual Results

The date changes to the day prior in Confluence, the date shifted to 22 but the release date is 23 in Jira

Other:

Tests were performed on server time with  UTC in both Jira and Confluence machines.

• Jira and Confluence user profiles set with UTC -works fine
• Jira and Confluence user profiles set with UTC  -   -works fine

• Jira user profile UTC- Confluence user profile  UTC+4 -  -works fine
• Confluence user profile UTC- Jira  user profile  UTC+4 - - issue replicated
• Confluence and Jira user profile set at  UTC+4 -  - issue replicated

Workaround

Set the timezone of every user to match the Jira default which is not suggested as the user base could be in different timezones for a company.

• Jira and Confluence user profiles set with UTC 
• Jira and Confluence user profiles set with UTC 
• Jira user profile UTC- Confluence user profile  UTC+4