git equivalent to pulling the most recent date from ChangeLog?

[sfeam <sf...@us...>]

Building from git tip fails to insert a valid date into
the "last modified" field.   This used to be pulled from the
top of ChangeLog and inserted into timestamp.h but that 
mechanism does not track the date of git commits.

On that note, I see that git commits keep their original date
(of construction?) rather than the date they were committed.
That means "git log" returns non-sequential dates in the
history of changes.  That does not seem like a great idea.
Is there a setting somewhere that tells git to stamp each
commit with the current date instead?

	Ethan