Divine Mercy Sunday
April 16
Rogation Days (Optional Fasting)
April 25
May 15, 16, 17
Ascension (Observed)
May 21st
Pentecost Sunday
May 28
Rogation - Latin rogare - "to ask"
Much like Ember Days, Rogation Days have been traditionally observed with prayer and fasting. The days of "asking" were traditionally offered for God to protect us, our family, and communities from calamities and other misfortunes.
This tradition goes back to the 5th century A.D., and made its way to the British Isles in the 7th century. The custom includes not only fasting, but processions and especially recitations of the Litany of the Saints.
Rogation Day observance (like Ember Days) is not mandated, and allowance is left to the various episcopal conferences around the globe. In the United States, the USSCB has recommended Rogation prayers for the care of creation and the blessing of gardens, orchards, and the like.
Rogation days are observed on April 25th (major observance) and the three "minor" days directly preceding the Solemnity of the Ascension (every year).
From our friends at CatholicRegister.org
The nature of the Lenten observance has changed significantly over the millennia. While fasting seems always to have been part of the paschal preparation, there was significant latitude around abstention in the early centuries of the church. Some Christians fasted every day during Lent; others, every other week only. The more austere fasters subsisted on one or two meals a week; but many found that cutting back to one repast a day was a sufficient sacrifice. And while many abstained from meat and wine, some ate nothing but dry bread.
Pope Gregory weighed in on this issue as well. He established the Lenten rule that Christians were to abstain from meat and all things that come from “flesh” such as milk, fat and eggs. And fasting meant one meal a day, normally taken in the mid-afternoon.
The prohibition around milk and eggs gave rise to the tradition of Shrove Tuesday or Mardi Gras (French for Fat Tuesday), which is celebrated the day before Ash Wednesday. On this day Christians would feast on the foods they were required to abstain from during Lent — gorging before the fast as it were — and pancakes became a popular meal for using up all the eggs and milk.
Over time, concessions were made to the rules around fasting. In the 12th and 13th centuries, church authorities such as St. Thomas Aquinas accepted that a certain amount of “snacking,” in addition to one meal a day, should be allowed, particularly for those employed in manual labour. Eating fish was eventually allowed and even the consumption of meat and dairy products as long as a pious act was performed to compensate for the indulgence.
Today the Catholic Code of Canon Law requires those 18 to 59 years of age to fast on Ash Wednesday and Good Friday.
"Spy Wednesday," also sometimes called "Holy Wednesday" is the day which tradition holds that Judas determined he would betray and deliver Jesus to the Temple authorities, and collected his advance of thirty pieces of silver.
Matthew 26 tells us:
Then one of the Twelve, who was called Judas Iscariot, went to the chief priests and said, “What are you willing to give me if I hand him over to you?” They paid him thirty pieces of silver, and from that time on he looked for an opportunity to hand him over.
Tenebrae (or "darkness" in Latin) is an evening service long held on Spy Wednesday in the Byzantine Catholic Rite, as well as the Latin Rite (until Vatican II), in which light is symbolically extinguished, marking the beginning of the extinguishing of the Light of the World. At Easter Vigil, Catholics still light candles to signify the reentry of the Light into the world.