Judaism (10)

Christianity (16)

Seasonal

Advent

Adventus

Four Sundays before Christmas (begins late November/early December)

4 weeks (approximately 22-28 days)

Commemorative

All Saints' Day

All Hallows' Day

November 1 (Western); First Sunday after Pentecost (Eastern Orthodox)

1 day

Joyous Celebration

Ascension Day

Feast of the Ascension

40 days after Easter (Thursday); some observe on 7th Sunday of Easter

1 day

Fast Day

Ash Wednesday

Day of Ashes

46 days before Easter (first day of Lent)

1 day (begins Lenten season)

Joyous Celebration

Assumption of Mary

Feast of the Assumption

August 15

1 day

Commemorative

Baptism of the Lord

Sunday after Epiphany (or January 13 in some traditions)

1 day

Joyous Celebration

Christmas

Nativity of Our Lord

25 December (Western); 7 January (Eastern Orthodox using Julian calendar)

1 day (liturgically); 12 days (Christmastide season)

High Holy Day

Easter

Pascha

First Sunday after first full moon following spring equinox

1 day (liturgically extends to 50 days until Pentecost)

Joyous Celebration

Epiphany

Theophany

January 6 (Western); January 19 (Eastern Orthodox on Julian calendar)

1 day (concludes 12 days of Christmas; begins Epiphany season)

High Holy Day

Good Friday

Great Friday

Friday before Easter Sunday

1 day (part of Holy Week and Easter Triduum)

Fast Day

Lent

Great Lent

Ash Wednesday to Holy Saturday (40 days not counting Sundays)

40-46 days (varies by tradition)

High Holy Day

Maundy Thursday

Holy Thursday

Thursday before Easter

1 day (part of Easter Triduum)

Commemorative

Palm Sunday

Passion Sunday

Sunday before Easter

1 day (begins Holy Week)

Pilgrimage Festival

Passover

Pesach

Nisan 15-22

7-8 days (7 in Israel, 8 in diaspora)

High Holy Day

Pentecost

Whitsunday

50 days after Easter Sunday

1 day (liturgically extended to octave or season in some traditions)

Pilgrimage Festival

Sukkot

Feast of Tabernacles

Tishrei 15-21 (22-23 in diaspora with Shemini Atzeret and Simchat Torah)

7 days (8-9 days including concluding festivals)

Islam (9)