2021 Calendary Week does not fit


I have noted that Calendary week does not fit with the real calendary week where W01/2021 starts on 4/01/2021 not 27/12/2020 as Gantt Projects shows.
Please, advise if possible to modify calendar on this platform

The first week of the year 2021 starts on 21/12/2020 in US. You need to choose the interface language of your country or English (United Kingdom) if you want English translation with European settings.

See also:

Really thankful,
Thank you