Roman Catholics celebrate the Mass of the Last Supper.
Holy Thursday, Good Friday, Holy Saturday - also known as the Triduum. It begins with Mass on Holy Thursday and ends with the beginning of Mass on Holy Saturday.
There are no "holy" months, but Catholics celebrate Lent.
Lent ends in the afternoon/evening right as the Mass of the Lord's Supper on Holy Thursday begins. That Mass begins the Easter Triduum which is the shortest season of the Liturgical year and comprises Holy Thursday evening, Good Friday, and Holy Saturday up until the start of the Easter Vigil.
Yes, Catholics bury their dead during Lent except during Holy Week after Holy Thursday until after Easter Sunday.
The day before Good Friday
Yes, Ascension Thursday is a holy day of obligation in the Catholic Church, meaning that Catholics are required to attend Mass on this day.
The last supper
Yes, Christmas is a holy day of obligation for Catholics, meaning they are required to attend Mass on this day to celebrate the birth of Jesus Christ.
Yes, on the Thursday before Good Friday, known as Holy Thursday or Maundy Thursday, Catholics and many Christians can eat meat. The fasting and abstinence typically associated with Good Friday begin on Good Friday itself. Therefore, there are no dietary restrictions on Holy Thursday.
No, the Mass is celebrated every day.
Yes, Holy Thursday is the prescribed day for the Chrism Mass in the morning that the Bishop holds with all his priests, although it is often moved to an early day in Holy Week. And then in the evening is the Mass of the Lord's Supper.