Shortcut to change date and time format to YYYYMMDD-HHMMSS

Here is an example (from iPhone, but it was created on macOS). Just edit the Format String.

[Edited by Moderator]

The receive part is automatically added when you set it as a Quick Action. It is in the Info tab. That is only necessary to put it in the Contextual Menu so you can Secondary click and select it from the Quick Actions in the contextual menu.

Just search for the names. If you type in Date, you will see all of the Actions related to dates.

Get Date is what I named my shortcut. Just creat a new Shortcut.

Here is an example with your desired date format:

The case of the date parts is important. For instance, if you use DD, it puts the Julian day instead of the day of month. If you build it today, it is somewhat confusing because the Julian day is 269, the first two digits matching the day of month.