ssh-agent w/timeout: does ssh-add reset that timeout?

[Kevin Layer]

I run ssh-agent like this:

  /usr/bin/ssh-agent -t 12h -s

If I run ssh-add will it reset the timeout period back to 12h for that
key, if it was already known to ssh-agent?

I ask because I've looked at the documentation and performed
exhaustive google searches for the answer and I've found no mention of
this issue anywhere.

Thank you.