The date month names are unfortunately not translatable; however, you can change the date format to YYYY-MM-DD instead.
Step 1
Find this line (at the top of the template code):
{% assign SETTING_date_format = "%b %e, %Y" %}
Step 2
Replace it with:
{% assign SETTING_date_format = "%Y-%m-%e" %}
Note: You can use the following website to help you get the needed format: https://www.foragoodstrftime.com/
Step 3
Save the template.