Some May Interfaith Inspirations:
Wicca/Pagan Beltane and Samhain ~ Northern and Southern Hemispheres ~ May 1st
Northern hemishere Pagans celebrate Beltane with maypole dances, symbolizing the mystery of the Sacred Marriage of Goddess and God. Southern hemishere Pagans celebrate Samhain (pronounced 'sow'inn'). Samhain, aka Hallowe'en, marks the Feast of the Dead. Many Pagans also celebrate it as the old Celtic New Year (although some mark this at Imbolc).
Baha'i 12th Night of Ridvan ~ May 2
A Baha'i commemoration of the twelve day period in 1863 when Baha'u'llah declared that he
was God's messenger for this age. Work is to be suspended on days 1, 9, & 12 of the festival.
Buddhist Visakha Puja ~ Wesak ~ Buddha Day ~ May 4
The most important of the Buddhist festivals. It celebrates the Buddha's birthday,
and, for some Buddhists, also marks his enlightenment and death.
Judiasm Lag B'Omer May 7 ~
Jewish observation of the counting of the day - the link - between Pesach and Shavout.
Interfaith ~ National Day of Prayer USA ~ May 7
An annual day of observance held on the first Thursday of May, designated by the United States Congress, when people are asked "to turn to God in prayer and meditation".
~ From Wiki
Islam Lailat al-Miraj ~ May 13
Islamic observance of Mohammed's night journey from Mecca to Jerusalem and his ascension to heaven.
Baha'i Declaration of the Bab ~ May 21
The Bab was the Forerunner of Baha'u'llah, founder of the Baha'i faith. His mission was to prepare the world for the coming of Baha'u'llah and he declared it in the evening of May 22 1844.
Christianity Pentecost ~ Whitsun ~ May 24
The seventh Sunday after Easter, commemorating the descent of the Holy Spirit upon the disciples and the birth of the Christian Church.
Judiasm ~ Shavout ~ May 24-25 (Begins sundown May 23)
Jewish celebration of Moses' descent from Mt Sinai with the ten commandments.
Plants and flowers are used in decorations.
Baha'i Ascension of Baha'u'llah ~ May 29 (Begins Sundown 28th)
Anniversary of Baha'u'llah's death in in 1892 near Akka, Israel.
Christianity Trinity Sunday ~ May 31
The first Sunday after Pentecost. Christians meditate on the nature of God as "Three in one".
Brief definitions and dates from the Interfaith Calendar by Delton Krueger ~ many, many thanks!