Non-Catholics possibly hear the term lent thrown around a lot by their Catholic friends and acquaintances. It is a time of penance. Penance is normally what Catholics call the satisfaction, usually judged by the priest, which you must perform as a condition of having your sins forgiven (John 20:23)Your sins are absolved during the last part of a confession called absolution. One website (https://aleteia.org/2022/05/27/what-is-the-catholic-meaning-of-penance/ )explains it this way “Absolution takes away sin, but it does not remedy all the disorders sin has caused. Raised up from sin, the sinner must still recover his full spiritual health by doing something more to make amends for the sin: he must “make satisfaction for’ or ‘expiate’ his sins. This satisfaction is also called ‘penance.’”
The self-imposed penance during lent is to train the will so that we are more prepared to resist temptation. It can consist of prayer, and offering (such as giving up meals so as to only have one full meal, formally mandated by the pope on Fridays during lent along with abstinence – the term for not eating meat, formally mandated by the pope also for every Friday not in lent. Since about the end of the twentieth century fast and abstinence were only required on Ash Wednesday (this coming Wednesday 22 February 2023) and Good Friday – the Friday before Faster, abstinence only all other Fridays during Lent.
Each year the date of Easter (from google) is calculated as follows: “The simple standard definition of Easter is that it is the first Sunday after the full Moon that occurs on or after the spring equinox. If the full Moon falls on a Sunday then Easter is the next Sunday.” Ash Wednesday is calculated by counting back 40 days excluding Sundays.
Before around 1962 or there about, you were forbidden by canon law, as I understand, from celebrating a wedding during either lent (preparation for the death and resurrection of Jesus Christ on Easter) or advent (4 weeks prior to Christmas in preparation for the birth of Christ) without special dispensation (e.g. someone dying of cancer and wanting to marry before a closely predicted death or going to war). The exact definition of lent from google is: “Lent is a 40 day season of prayer, fasting, and almsgiving that begins on Ash Wednesday and ends at sundown on Holy Thursday. It’s a period of preparation to celebrate the Lord’s Resurrection at Easter.”