is it a bug or a feature? re:time zone differences, laptops, and suggestion for a new option

[Robert Scholten]

>Hi,

I am using rsync to back up some files from a WinXP laptop to a Linux 
server.  The two machines are in different time zones (8 hour 
separation).  It seems that rsync wants to do a full checksum on every file 
because it thinks their time stamps are different.

Example:
         GMT is 9am, Local time (Netherlands) 10am, remote time (Australia) 8pm

In this case, the file was created and copied to both machines with the 
same timestamp (e.g. 8pm) when both machines were in the same timezone 
(Australia).  Then I changed countries with my laptop, and ran 
rsync.  After rsync, the remote (Linux) file has a new timestamp which 8 
hours earlier (e.g. 10am).

I guess that in some sense, rsync "thinks" they were created at different 
universal times, and after rsyncing, they are matched to the same UTC.

This is OK after I have done it once, but would it be possible to tell 
rsync that if the timestamp difference is the same as the current time 
difference, it should ignore?  Or just change the timestamp rather than 
doing a full checksum?  I could write a script to run on the Linux box, to 
change the timestamps by the 8-hour time diff, and revert when I return to 
Australia, but surely this happens regularly to other people with laptops?

Or am I totally confused?

Any help will be appreciated.
Thanks,
Rob.



--
Robert Scholten
Eindhoven University of Technology
Physics Department, building N-laag room g2.02
P.O. Box 513, 5600 MB Eindhoven
The Netherlands

Tel:    +31 40 247 4242
Mobile: +31 611 430 467
Fax:    +31 40 245 6050

email: r.scholten at physics.unimelb.edu.au
http://www.ph.unimelb.edu.au/~scholten