Ash Wednesday is Today: Day of Repentence

For Christians, and specifically Catholics, today is Ash Wednesday and marks the first day of Lent, a time of repentence and fasting. Today is especially marked for fasting, as only one full meal and two smaller meals not equally the one meal in size are permitted to be eaten. Also, Catholics are obligied to abstain from meat.

At mass today, Catholics will receive a cross on their foreheads using ashes. This comes from the Biblical practice of people covering themselves in ashes as penitents. Also, a mark on the forehead represents ownership, so a cross represents that we are servants of Christ.

The following information is very valuable, and is from Jimmy Akin, from Catholic Answers Live:

On the first day of Lent, this signing is done with ashes because they are a biblical symbol of mourning and penance. In Bible times the custom was to fast, wear sackcloth, sit in dust and ashes, and put dust and ashes on one's head (cf. 1 Sam. 4:12; 2 Sam. 1:20, 13:19, 15:32). Ashes also symbolize death and so remind us of our mortality. When the priest uses his thumb to sign one of the faithful with the ashes and says, "Remember, man, that thou art dust and unto dust thou shalt return," he is echoing God's address to Adam (Gen. 3:19; cf. Job 34:15; Ps. 90:3, 104:29; Eccles. 3:20). This phrase also echoes the words at a Catholic burial, "Ashes to ashes; dust to dust," which is based on God's words to Adam in Genesis 3 and Abraham's confession, "I am nothing but dust and ashes" (Gen. 18:27).

Catholics are not required to have their foreheads signed with ashes. It is, though, strongly advised as a visible spiritual reminder that encourages us to adopt an attitude of prayer, repentance, and humility.

Neither is Ash Wednesday a holy day of obligation. Holy days are either commemorations of particular events (such as the birth of Christ), particular people (such as Jesus' earthly father, Joseph), or important theological concepts (such as the Kingship of Christ). Ash Wednesday does not commemorate any event and could be said only indirectly to commemorate a Person (Christ), since it is the beginning of preparation for the greater celebrations of Christ's saving work that follow. However, attending Mass is a fitting way to mark the beginning of penitential season of Lent. Also, it is a day of fast and abstinence.