The 17th of February in 2018 is a date to be kind because it's Random Acts of Kindness Day. This is an unofficial holiday in the USA. It aims to encourage people for acts of goodness and kindness. There is another Random Acts of Kindness Day in New Zealand on September, 1 annually, but it has nothing to do with this one.
Kindness is being friendly and polite to others, maybe doing something nice for them. If you like to take part in the Random Acts of Kindness Day you might for example bring some cake to the office today and share with your colleagues. You might give food to homeless people, leave a book in public, so someone would find it, let somebody go first in the supermarket or whatever comes up to your mind.