Is it correct to place inside a UL list like a DIV?

Question

css

And in general, the situation due to which the question was born:
I want to place a date window in a two-line form at the end of the navigation line and I don’t understand how to align it and raise it higher

.main-menu li{
  display:inline;
  margin-left:50px;
}
.date{
  color:white;
  font-size: 90%;
  float: right;
  margin-right: 40px;
  text-align:center;
  border:solid 1px;
  padding:5px;
}

After pulling out the div for navigation, this is what happened.

Answer 1

not right.