Is there a reward for the Friday ghusl, if performed on another day, similar to its reward on Friday? And is it better to perform it on any other day before the following Friday, or to wait for the next Friday, if someone missed it on Friday?

The encouragement to perform ghusl (definition) (ritual bath) on Friday is established by the hadith (definition): "He who performs ghusl on Friday, similar to the ghusl for janabah (definition) (major ritual impurity), and then goes (to the mosque), it is as if he sacrificed a large camel..." This ghusl is specific to Friday. Therefore, whoever misses it is not legislated to make it up, nor will they attain its reward by performing ghusl on another day. The ghusl for Friday is a Sunnah (definition) (recommended act) according to the majority of scholars, not an obligation.