May is Asian Pacific American Heritage Month in the United States. The month of May was chosen to commemorate the immigration of the first Japanese to the United States on May 7, 1843, and to mark the anniversary of the completion of the transcontinental railroad on May 10, 1869. The majority of the workers who laid the tracks on the project were Chinese immigrants.
May is Older Americans Month, established in 1963 to honor the legacies and contributions of older Americans and to support them as they enter their next stage of life.
May is Jewish American Heritage Month, which recognizes the diverse contributions of the Jewish people to American culture.
May is Mental Health Awareness Month (or Mental Health Month), which aims to raise awareness and educate the public about mental illnesses and reduce the stigma that surrounds mental illnesses.
May 1: Beltane, an ancient Celtic festival celebrated on May Day, signifying the beginning of summer.
May 2: Orthodox Easter (also called Pascha), a later Easter date than observed by many Western churches.
May 3: Saints Philip and James, a Roman Rite feast day for the anniversary of the dedication of the church to Saints Phillip and James in Rome.
May 5: Cinco de Mayo, a Mexican holiday commemorating the Mexican army’s 1862 victory over France at the Battle of Puebla during the Franco-Mexican War (1861-1867). This day celebrates Mexican culture and heritage, including parades and mariachi music performances.
May 6: National Day of Prayer, a day of observance in the United States when people are asked to “turn to God in prayer and meditation.”
May 9: Laylat al-Qadr, the holiest night of the year for Muslims, is traditionally celebrated on the 27th day of Ramadan. It is known as the Night of Power and commemorates the night that the Quran was first revealed to the prophet Muhammad.
May 12-13 (sundown to sundown): Eid al-Fitr, the first day of the Islamic month of Shawwal, marking the end of Ramadan. Many Muslims attend communal prayers, listen to a khutuba (sermon), and give Zakat al-Fitr (charity in the form of food) during Eid al-Fitr.
May 13: Ascension of Jesus or Ascension Day, is celebrated as the ascension of Christ from Earth in the presence of God within most of the Christian faith.
May 16-18 (sundown to sundown): Shavuot, a Jewish holiday that has double significance. It marks the all-important wheat harvest in Israel and commemorates the anniversary of the day when God gave the Torah to the nation of Israel assembled at Mount Sinai.
May 17: International Day Against Homophobia, Transphobia and Biphobia, a global celebration of sexual-orientation and gender diversities.
May 21: World Day for Cultural Diversity for Dialogue and Development, a day set aside by the United Nations as an opportunity to deepen our understanding of the values of cultural diversity and to learn to live together in harmony.
May 22-23 (sundown to sundown): Declaration of the Báb, the day of declaration of the Báb, the forerunner of Bahá'u'lláh, the founder of the Bahá’í faith.
May 23: Pentecost, the celebration of the giving of the Ten Commandments by God at Mount Sinai.
May 26: Buddha Day (Vesak or Visakha Puja), a Buddhist festival that marks Gautama Buddha's birth, enlightenment and death. It falls on the day of the full moon in May and it is a gazetted holiday in India.
May 29: Ascension of Bahá'u'lláh, commemorates the ascension of Bahá'u'lláh, the founder of the Bahá’í faith.
May 30: Trinity Sunday, observed in the Western Christian faith as a feast in honor of the Holy Trinity.
May 30: All Saints’ Day, celebrated by many Eastern Christian churches on the first Sunday after Pentecost, in recognition of all known and unknown saints.
May 31: Memorial Day in the United States, a federal holiday established to honor military veterans who died in wars fought by American forces.