[Help-bash] set time

[Max]

Is there any *direct* command to shift time in bash (using date or another,
preferably not too unpopular, console binary)?

Say, it's 09:00 now and the command makes it 11:30 *without* me having specified
"11:30" but only provided the command the 2h30m interval.

Note that any "indirect" methods may need complicated ways to keep
track of the milliseconds lost while running them. It even took around one
second in some virtual machine guest systems. So I'm hoping bash etc. happen to
have the magic needed to do the job for me.