The signature of calligraphy also depends on the overall layout. If there is enough space, write more. If there is not enough space, just write the time and name. For example, this calligraphy by Mr. Qi Gong:
The signature here is "Autumn Qi Gong in 1985" and then two seals are added, one is Yangwen and the other is Zhuwen. If you don't know about seals, you can read this article "Calligraphy" "Knowledge about work seals and frequently asked questions (including the use, types and maintenance of ink pads, etc.)", I believe it will be helpful to you!