Does your country's postal service refuse to deliver mail on certain days?
https://yle.fi/uutiset/osasto/news/posti_stops_regular_mail_deliveries_on_tuesdays/9740698
Also unrelated question, what's the VAT (value added tax) in your country? In Finland it's 24% for most products, but 14% for food and 10% for medicine, certain services and magazine subscriptions.
>>77577736
Yes, no mail on Sundays
0% VAT