It is 9th Muharram of the Islamic calendar today. So plz dont forget to fast today and tomorrow as it is recommended by the Prophet Muhammad (peace be upon him).
The Prophet (peace and blessings of Allaah be upon him) came to Madinah and saw the Jews fasting on the day of ‘Ashoora’ [10th Muharram].
He said, “What is this?”
They said, “This is a good day, this is the day when Allaah saved the Children of Israel from their enemy and Moosa fasted on this day.”
He said, “We are closer to Moosa than you.” [Sahih al-Bukhari]
So he fasted on this day and told the people to fast.
It is best to fast not just on the day of Aashoora but also adding a day before or after it fasting. As the Prophet (peace be upon him) said, 'If I am (still) here next year, then certainly I shall fast the ninth (day of Muharram).' [Muslim]
We fast on this day out of respect for it, and it is Sunnah not obligatory. But the reward is GREAT. Again in the Prophet's words, (peace be upon him).
“Fasting the day of ‘Arafah I hope Allaah will expiate thereby for the year before it and the year after it, and fasting the day of ‘Ashoora’ I hope Allaah will expiate thereby for the year that came before it.” [Muslim]
That is, forgiveness from all the (minor) sins commited during the year before it inshaAllah. And the thing to remember is that all the major sins will still need repenting.
Have a great day, May Allah forgive us all of our sins, and make us do deeds that He loves, aameen.
Don't go, read some more here :)