David posted
On Tue, 29 Oct 2019 20:29:26 +0000, newshound wrote:

I do incremental backups of a couple of datasets with simple batch files
using Robocopy /MIR. These normally work fine, except after the clock
change when they back up everything on the grounds that the target files
are all "older". IIRC they do this for both directions of clock change.
No huge deal to "live with it" but interested to know if there might be
a fix.

Slightly increase the backup interval?

I assume that if you are backing up hourly or less then this might cause
an issue on clock change (or perhaps if you are backing up around
midnight) but I assume that if you make sure that your backups are more
than an hour apart and that they don't take place during the hour back/
forward window then all the files should be accurate?

I can see that files modified just before and during the time going back
an hour could have incorrect relative times, but anything modified longer
ago shouldn't be picked up.

No, that's not so. I got the same thing as the OP even though I only
backup every couple of days, and well outside the clock-change period.

Would be nice if there was a setting to use UTC date/time instead of GMT/
BST though.

That's what I was looking for in the xcopy parameters, but it's not
there.

--
Evremonde