Is Sunday actually the only day that people seem to show their spiritual side?

Not for true Christians. Really it is a way of life. With Bible councel affecting evety phase of life. It guides us in showing how to have the fullest, best form of life. Motivating us for our best benefit.

Examine the 632 Mosaic Laws in the covenant with Israel. There were several sanitary and dietary laws protecting Israel from sickness from germs and bacteria. Humans were not aware of those until well past our US Civil War around 1865. We did not know, but 4,000 years ago, God did.

Looking closely, you will find all of God's laws are for our benefit.

The Sabbath was under the Mosaic Law. All it said was people to stop their normal work to appreciate as a family, God's wonderful creations, period.

At Matt. 5:17, Jesus explained, he came to GULFILL the Mosaic Law, not destroy it. With his human sacrifice, he did that. Now we are no longer under that Mosaic Law, with its Sabbath.

For True Christians, every day is one of wonder and giving thanks for all creation. Not just 1.

I know for a fact, that Jehovah's witnesses are spiritual and attend meetings 2X a week...it used to be more, but then many had conflicting jobs that interfered and that was changed a few years ago.

Yeshua provides a relstionship every day.

Catholic parishes typically offer mass seven days a week, but the other six days have a nonspiritual mass?

I totally forgot that it was Sunday when I woke up this morning. I plan on going to my friend's church but I decided to wait a couple of weeks before going there because I showed up with him to an event last week and I don't want people to think we are dating - which they might assume if I follow him around everywhere.

Some people. Others don't make it an issue and other than that people can be spiritual daily. I think one thing that confuses the issue is that people tend to have a preset idea of what spiritual means and never seem to question it.

For christians, its Saturdays n Sunday plus Days of obligations...

That was the whole idea, to get holy on Sunday; the other days are for practical matters. If you get really really holy on Sunday that will tie you over on the other six days. This is why is was customary to kill a person who was doing stuff that wasn't holy on Sunday. (Then again what the hell do I know.)

That rather depends on one's religion, doesn't it?

No