datetime

[Terry Reedy]

On 9/13/2012 11:19 AM, Max wrote:
> How do I set the time in Python?

If you look up 'time' in the index of the current manual, it directs you 
to the time module.

"time.clock_settime(clk_id, time)
Set the time of the specified clock clk_id.
Availability: Unix.
New in version 3.3."

You did not specify *which* time to set, but ...

"time.CLOCK_REALTIME
System-wide real-time clock. Setting this clock requires appropriate 
privileges.
Availability: Unix.
New in version 3.3."

Chris already suggested an approach for changing your process's idea of 
time. However, setting time.timezone seems to have no effect

> Also, is there any *direct* way to shift it?

If you mean time.clock_shift(clk_id, shift_seconds), no.

time.clock_settime(clk_id, time.clock_gettime(clk_id) + delta_seconds)

> Note that any "indirect" methods may need complicated ways to keep
> track of the milliseconds lost while running them.

Whay would a millisecond matter? System clocks are never synchronized to 
official UTC time that closely without special hardware to receive time 
broadcasts.

> It even took around one
> second in some virtual machine guest systems. So I'm hoping Python happens to
> have the magic needed to do the job for me.

The above should be well under a second.

-- 
Terry Jan Reedy