Assemblies and conventions are the closest event to a 'Holiday' for Jehovah's Witnesses.
It's like a family reunion of sorts - with your 'NEW' family. We travel together, we spend the whole day together, we eat together, we sleep under the same roof together, we all dress (look) alike, we talk alike, we read together, we take pictures of each other, we find our future husband or wife, we hug, laugh, cry, sing & reminisce, talk about the dead and the sick members of our 'family', congratulate the newlyweds and new parents, listen to experiences and hardships of our 'family'; applaud their accomplishments, strength and determination.
Meanwhile the aged non-JW parent sits alone in the living room wishing that his children and grandchildren would come visit him for one weekend this year...but their lives are just so busy now-a-days.