Is it superstitious to get married and watch the Gregorian calendar?

From a folklore point of view, not really. Everyone has such a program, which is auspicious.

Judging from the current empirical science, all this can't be proved, and it seems to be attributed to superstition. In fact, we can't rashly deny what we don't know.

The world we advocate at present is materialistic, and only what is visible and verifiable is scientific. This premise itself is unscientific.