I sort of agree with @MacBlank in that we shouldn't have to concentrate on one group for one day. However Black Lives Matter is (and was born from) a wholly different movement. I do agree with Black History month - it is a time for people who have had a lot of their history taken from them, to remember the good, and the reasons why it happened.
International Womens day, International Mens day, TransWeek, LBGTQ2+ Week, etc should not be required in my opinion, and in some circumstances can actually perpetuate the practise of ostracising people.
In my opinion we should simply celebrate people, no matter what sexual bits they have, what bits they enjoy (or not) or what they identify as.
People are people, and many of us are truly awesome and deserve the recognition and celebration.