01st

Beltane (Wiccan, Celtic)
Celebration of Asherah (Babylonian)
Rowan Witch Day (Finnish)
May Day (European)

02nd

Fire Festival of Bona Dea (Roman)
Floralia (Roman)
Elena's Day (Welsh)
St. Helen's Day (British)

03rd

Cruces (Mexican)
Corn Festival (Native American)

04th

St. Monica's Day (Irish)
Veneration of the Thorn (Irish)
Festival of Sheila Na Gig (Irish)

05th

Feast of Banners (Japanese)
Cinco de Mayo (Mexican)
Feast of the Dragon (Chinese)

06th

New Moon
Eyvind Kelve (Norse)
Enlightenment of the Buddha

07th

Helston Furry Dance (Cornish)

08th

Stork Day (Danish)
Moslem New Year

09th

Lemuria (Roman)
Feast of Artemis (Greek)

10th

Tin Han's Day (Chinese)

11th

Ceremony for Rain (Guatemalan)
Mother's Day
St. Mamertius (German)

12th

Festival of Sashti (Indian)
St. Pancras (German)

13th

Our Lady of Fatima (Portugese)
St. Servatius (German)

14th

Isis' Day (Egyptian)
Apollo's Birthday (Greek)
St. Benefatius (German)
Goddess Tithe Day (North African)

15th

Feast of Isidro (Filipino)
Cold Sophie (German)
Maia and Mercury's Day (Roman)
Festival of Vesta (Roman)
Rain Dance Night (Guatemalan)

16th

Savitu-Vrata (Indian)
St. Brendan the Navigator (Celtic)

17th

Dea Dia (Roman)
Mut L-Ard (Maroccan)

18th

Pentecost (Christian)
Feast of Pan (Greek)

19th

Feast of Pudenciana (Mexican)
Victoria Day (Canadian)
Kallyntaria Begins (Greek)
Plynteria Begins (Roman)

20th

Mjollnir (Germanic)
Okinaga-Tarashi-Hime (Japanese)

21st

Plato's Birthday (Greek)
Day of Tefnut (Egyptian)

22nd

Full Moon
Ragnar Lodbrok's Day (Odinist)
Chung K'uei's Day (Chinese)
Munychia (Athenian)

23rd

Semik (Russian)
Declaration of the Bab (Baha'i)
Rosalia (Roman)

24th

The Three Maries (French)
The Three Mothers (Celtic)
Hermes Trismegistus (Roman)
Thargelia (Roman, Greek)
Celebration of  the Horae (Greek)

25th

Assassination of Edmund I (Anglo-Saxon)
Trinity Sunday (Christian)
Whitsunday (European)
Celebration of the Tao, Mother of the World (Chinese, Japanese)

26th

Memorial Day (USA, observed)
Day of Chin-hua-fu-jen (Chinese)
Festival of Diana Begins (Roman)

28th

Kallyntaria Ends (Greek)
Plynteria Ends (Roman)

29th

Oak Apple Day (English)
Ascension of Baha'u'llah (Baha'i)
Ambarvalia (Roman)

30th

Memorial Day (USA)
Frigg's Day (Odinist)
Feast of the Queen of the Underworld Begins (Roman)
Feast of the Queen of  Heaven (European)

31st

Day of Oggum (Cuban)
Day of Santa Petronilla (Mexican)
Festival of Diana Ends (Roman)
Feast of the Queen of the Underworld Ends (Roman)