Languages month/year is shown incorrectly in date picker

Desciption

When using a date picker in a Confluence page in other languages the month is shown incorrectly. It appears to have a null or blank after the month and year.

Environment

Confluence 7.0.1

Steps to Reproduce

1. Change the profile language to a non US/UK language
2. Create a new Confluence page and add a date
3. The picker is shown with the month and the incorrect translation or bug

Expected Results

The month and year is shown correctly without any suffix.

Actual Results

In Russian, the month and year is shown as "Сентябрь 2019нет"
In German, the month and year is shown as "September 2019Null"
In Finnish, the month and year is shown as "Syyskuu 2019tyhjä"

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available