git commit --amend --date=now --no-edit
to change the date of the last (local) commit. –no-edit for not modifying the commit message, otherwise it will open a text editor to enter new commit message.
git commit --amend -m '#572: Fixed crash'
to change the message of the last (local) commit.
git merge feature/CoolFeature --no-ff
merge branch ‘feature/CoolFeature’ without fast-forwarding current branch
git merge feature/CoolFeature --squash -m '#573: CoolFeature'
will combine all the commits of ‘feature/CoolFeature’ into one single commit and merge that commit to current branch.