Issue Summary

Excel preview showing wrong date if using yyyy/m/d(aaa) customized format.

Steps to Reproduce

1. Create a Excel file
2. Input '2021/4/28' in Excel
3. Set the format as customized: 'yyyy/m/d(aaa)'
4. Save the file
5. Upload the excel file into a ticket, and preview the Excel file in ticket.

Expected Results

Showing 2021/4/28(Wed) as setting in Excel

Actual Results

Showing 2021/2/16(wed)

Workaround

Set the text formats for the dates, or download the attachment and view it.