io: to_excel leads to TypeError when index with tz

[dacoex]

I would like to save a df with the following index to an Excel file:

it shows the following error:

TypeError: Timestamp subtraction must have the same timezones or no timezones

[jorisvandenbossche]

@dacoex Thanks for the report!
I suppose this is a duplicate of #7056

This is not really implemented at the moment (excel also does not support timezones, so an implementation would something be like a removal of the timezone + warning).
For now, you can convert it to naive timestamps yourself before exporting to excel.

[dacoex]

Just as reference for anyone:
use

df.tz_localize(None)

http://pandas-docs.github.io/pandas-docs-travis/timeseries.html#time-zone-handling