Periods not correctly represented in to_excel() with monthly PeriodIndex · Issue #4133 · pandas-dev/pandas (original) (raw)

When I have a Panel with a PeriodIndex with freq="M" and I use mypanel.to_excel(), then the PeriodIndex gets represented as YYYY-MM-DD in the output Excel file. I would expect it to be rather YYYY-MM.

Is this a bug or a feature?