Is it possible to formatting bold in excel formula?

Since you can apply rich text formatting to the cells that contain the formula, why not use more than 1 cell and eliminate the display of line between them so the 2 cells look like 1. Then put the word "Date:" in the first cell flush right margin and in the cell next to it, put the formula to gather the date, formatting the cell to flush left margin, and bold that cell.

You cannot format text to italic, but you could change the basic latin letters to corresponding italic unicode characters:

    Function ITALIC(orig As String) As String
        Dim result As String
        Dim c As Long
        result = ""
        For i = 1 To Len(orig)
            c = WorksheetFunction.Unicode(Mid(orig, i, 1))
            If c > 64 And c < 91 Then c = c + 120263
            If c > 64 And c < 123 Then c = c + 120257
            result = result & WorksheetFunction.Unichar(c)
        Next i
        ITALIC = result
    End Function

You may change the text to many other forms as well. https://lingojam.com/ItalicTextGenerator

Seeing as there are a lot of requests for this functionality, maybe Microsoft should add that to a future update of Excel.