Datepicker calendar selects wrong month as default in MEST timezone

Overview:
With my system timezone set to middle european summer time the datepickers calendar shows the wrong default month when setting the date. When editing an existing date this also happens. It always selects one month earlier than expected.
If I set my system timezone to EDT the error doesn't occur.
Steps to Reproduce:

1. Log into https://folio-snapshot.aws.indexdata.com or https://folio-testing.aws.indexdata.com with your system timezone set to MEST (middle european summer time, e.g. Berlin)
2. Select the agreements app and click the New button
3. In the Agreement period 1 card click the calendar icon on the right of the Start date field

Expected Results:
Today's date should be selected in the displayed calendar
Actual Results:
The selected date is one month earlier (e.g. today is August 10th, but July 10th is selected).
If you select this suggested date, nevertheless the actual date is filled in the Start date field
Additional Information:
see screen movie attached
Interested parties: middle europeans