Empty date in LaTeX template

[twsh]

This recent change to the Beamer template puts \date in a conditional: 3f1f58e

I think that the motivation for the change would apply just as much to the LaTeX template: #10687 (comment)

I also wonder whether \author should also be in a conditional, in both templates, for similar reasons.

One thing to note about the date changes is that it's now not easy to have a slide deck or document without a date printed. (I think depending on the class/theme used.)

[jgm]

I'll put both of these under conditionals.

[jgm]

Scratch that. After implementing this, I realized that we should NOT do this, and I plan to revert the change to beamer as well.

Reason: if you don't include \date, a date is automatically generated. We don't want that. We want to keep the earlier behavior, which causes no date to appear when date is not specified in the document.

I think an empty \authors{} is pretty harmless, but let me know if there is some drawback to it.