Today is the only holiday celebrated by Jehovah's Witnesses, the memorial of Jesus' death also known as the Lord's evening meal. If I recall my scriptures correctly, Jesus added a new ritual after the Passover meal. This new ritual is called communion by other Christian sects. I can't remember the reasoning for JWs doing the memorial every year instead of every month or week.
After I moved, I did attend the memorial at the local congregation. I felt very uncomfortable because I didn't know anyone there. You see, I think that was the time that I wanted to attend with my mother. But I guess she was more interested in hanging out with her JW friends and not assisting her "lost" daughter. Growing up, the memorial was a huge deal. We got new clothes and went out to dinner afterwards, the JW version of Easter, sorta. We would try to dress alike or wear the same colors. I mean, this was the only holiday we celebrated so we tried to make it special.
As you may have guessed, I'm no longer JW and I will never be again. I do not believe that the bible is God's word. I believe that Jesus may have been a historical person but not specially divine. I have also done my own personal research on JW, stuff that we wasn't taught in the Kingdom Hall.
The religion now known as Jehovah's Witnesses can trace its roots to a group of men just like any other religious movement. Charles Taze Russell, raised Presbyterian, hooked up with some Millerites and they had a bible study. Russell particularly agreed with Nelson Barbour, a Millerite Adventist. However, they had disagreements over bible doctrine and parted ways. Russell called his group Bible Students. Russell died in 1916. Joseph Rutherford took over. Apparently, Rutherford made some changes that were in direct contradiction to Russell's teachings. In 1931, the religion under Rutherford became known as Jehovah's Witnesses. Those faithful to Russell's teachings are still around today known as various bible student groups.
There may have be more recent branches from JW as people get disillusioned and leave. I was baptized in 1992 at 17 and disfellowshipped in 1995 for committing fornication (I was pregnant with my son). I am still being "punished" for a promise I made to this organization when I was a minor. Even legally, minors cannot enter into a contract. I'm thinking of writing a letter declaring that my baptism is null & void, you know, for therapeutic reasons. I know the Watchtower Bible & Tract Society could care less.
JWs believe like most other Christian religions that they are the only truth. Once you are baptized in, you cannot leave easily. That is, if you ever decide that you don't want to be a JW anymore, your life will be ruined. You will have to disassociate yourself which means that your Witness friends can't talk to you anymore. If you grew up as a JW like me, you will have no friends.
I'll stop before I sound even more bitter than I am. I need to prepare for my full moon ritual anyway.