Legal information

Legal notice

Responsible for this website
Pierre Christian Ulrich Singer, Entrepreneur individuel (EI)

Singer Shamrock Enterprises is a brand of Pierre Christian Ulrich Singer, Entrepreneur individuel (EI).

Contact and service address

87 Impasse de la Petite Trémaillère, 71500 Saint-Usuge, France
+33 6 85 57 56 02
pcusinger@gmail.com
SIREN 131 236 408 · RCS Chalon-sur-Saône

Hosting

GitHub Pages · GitHub, Inc.
88 Colin P. Kelly Jr. Street, San Francisco, CA 94107, United States

Privacy

Dates, calculations and training answers are processed in your browser. This site does not send your entered dates or answers to a server. It has no user accounts, analytics, advertising trackers or payment forms.

Only your selected language may be saved in local browser storage. Exercise progress lasts only while the page stays open. You can remove the language preference by clearing this site’s browser data.

Serving the website involves technical connection data, such as IP addresses, processed by the hosting provider. See the host’s privacy policy. When you follow an external link, the destination site’s own privacy information applies.

Hosting provider’s privacy policy

Terms of use

Bdaymethod is a free educational tool for practising calendar arithmetic. Gregorian calculations are provided for years 1–9999, including dates before local adoption of that calendar.

The site and its exercises are checked carefully, but uninterrupted availability and complete freedom from errors cannot be guaranteed. Check dates against an authoritative calendar when accuracy is consequential.

The site’s original text and design are protected where applicable. This does not claim ownership of calendar facts or John Conway’s mathematical method. External booklets are separate offers with their own purchase terms.