Sauna Day is observed in Japan every March 7 and is also known as the Day of Sauna and Health. Established by the Japan Sauna Spa Association (JSSP), the holiday aims to promote Japanese bathing culture and educate the public about the health benefits of saunas. The celebration is rooted in Japan's long-standing traditions of communal bathing, which include onsen (natural hot springs) and sentō (public bathhouses). The modern sauna gained popularity in Japan after being introduced by Finnish athletes during the 1956 Melbourne Olympics and later at the 1964 Tokyo Olympics. The date March 7 was chosen because the Japanese numbers three ("san") and seven ("nana") phonetically resemble "sauna." In addition to promoting sauna use, JSSP collaborates with the Japanese Red Cross Society for a nationwide blood donation campaign, advising participants to avoid sauna use for 24 hours after donating blood.