Issue Summary

When using Mexico Default Timezone DateTime fields are converted 1 hour ahead on Excel and GSheets Export.

This may be caused due to Daylight Saving time. However, the Mexican Government has declared that Mexico will only have one Standard time from 2023, and the time will not be adjusted as per the DST adjustment.

Time-related data are getting affected, thus impacting the business.

Steps to Reproduce

1. Set the Atlassian Account timezone preference - or Default user time zone on Jira General Configuration - to (Mexico/Mexico City GMT-6) 
2. Go to the 'Advanced Issue search' page
3. Click on the Excel Icon (Open in Microsoft Excel)
4. Check for Date/Time fields.

Screen recording of the problem experienced: Incorrect Time on Excel Export

Expected Results

As Mexico eliminated the DST (Daylight saving time), no automatic changes should occur to the time set in the date/time fields when exporting and reviewing data via Excel.

Actual Results

When using the Mexico timezone, if there is a field filled in with April 03, 2023, 09:00 AM in JIRA, after exporting to Excel the field is converted to April 03, 2023, 10:00 AM, for example.

Workaround

• Using a different Time zone with a similar GMT in which Daylight Saving rules are not applied (for example, Guatemala GMT-6).
  • Screen recording of the workaround being applied: Changing Timezone Settings

• Exporting Issue through other native option (eg CSV) since it's unaffected by the bug.