g:timestamp_rep syntax

The timestamp.vim plugin works beautifully. It automatically updates a line in the file that I edit, giving the second when I last re-saved the file.

But how does one change the format of the timestamp?

.vim/doc/timestamp.txt

says, about the format:

Default: '%a %d %b %Y %I:%M:%S %p %Z'

<snip>

To change this value, either set g:timestamp_rep in your {.vimrc} or set b:timestamp_rep for the buffer in question.

Can anyone provide an example of the syntax whereby one explicitly sets g:timestamp_rep in the .vimrc?

For instance, I tried inserting the following line into my .vimrc

set g:'%a'

and this threw an error when I opened a new file in vim.

Thanks for any insight

Jacob Wegelin